Heat TreatToday publisher Doug Glenn and Marc Glasser of Rolled Alloys on why choosing the cheapest material is not always the best way to go. Listen to some of the practical tips Mr. Glasser gives for choosing the right alloy for your application.
Below, you can either listen to the podcast by clicking on the audio play button, or you can read an edited transcript.
The following transcript has been edited for your reading enjoyment.
Doug Glenn (DG): We're going to talk today about something that Marc and I had talked about that kind of caught my attention that I thought might be of interest to our listeners, and that's this whole idea that sometimes buying the cheapest material isn't always the best option. So, that's the topic, but, before we do that, Marc, I want you to tell our listeners and/or viewers a little bit about yourself, your background, and what you're currently doing.
Marc Glasser (MG): I have been a metallurgist or material scientist for forty years. Next month will be exactly forty years since I graduated from Rensselaer Polytechnic Institute with a bachelor's degree in materials engineering. After ten years of working, I went, simultaneously, to a job and to night school for five years and I obtained my Master of Science in material science from, then, Polytechnic University which is now known as the NYU School of Engineering. I've been working in all areas of metallurgy and material science. I've worked in rolling, I've worked in forging, I've worked in powder metallurgy, and I've worked in heat treating laboratories. I'm currently working in metallurgy of heat resistant materials and applications of these alloys in industry.
School of Engineering at NYU
DG: Let's jump in then, Marc. I want to talk to you a little bit about this contention that you and I talked about that sometimes, but not all the time, expensive is better and buying the cheapest isn't always the best. In a nutshell, what are you trying to say on that?
MG: I'll take it even one step further: Expensive is cheaper. Let me expand on that. You have a part and it's a certain price and you know you have a life of two years. . . so that's cost X. You have alloy #2 that's going to cost 60% more. It's going to have a life of eight years. Again, you're going to pay 60% more for this part than you would for the first part of the less expensive alloy. But, over the operating life of that less expensive alloy, you're going to have to replace it three times. You're going to use four separate components. So, 60% of the cost times four, you're spending 240% more than you would spend on one component that's a little more.
It's cheaper up front, but over the entire life cycle of the part, buying four more parts of the cheaper one is a lot more expensive.
DG: Let's talk about some of those hidden factors that come into play when you're analyzing the true cost of selecting those materials. Do you have a couple of examples?
MG: Absolutely. The most stark example, that we made our first case history on, is radiant tubes. For years, the alloy of choice on radiant tubes was a wrought 601 thin wall and you get about two years on it in a typical furnace. Then the casting industry came in and, because of limitations of the machinery, they had to go with a heavier wall that was three times as thick and that cost 30% more, but it got four years of life. Now, there's newer technology and they can cast it a lot thinner, but thinner doesn't last as long. So, for the wrought tube, you're talking about 1/8 of an inch wall thickness. With cast, for the four-year version, is about 3/8 of an inch and if you go down to 1/4 inch or less, you get maybe two or two-and-a-half years and if you go to the more expense wrought alloy, (again, you're talking about 1/8 inch wall), it's 60% more than the original one, 30% more than the cast, and you get eight years out of it.
Now, again, these numbers are based just on the cost of the material. But, you've got to dig a little deeper because you're not capturing the true savings of using the more expensive material because, think of this: If you've been in a heat treating shop and you know your carburizing furnaces, you have to turn it off, cool it down, let it air out because you've got a carbonaceous gas in there and any residual carbon monoxide, if you go in there, you're going to asphyxiate.
The bottom line is, the turnaround can take up to a week. Each time you have to go down for a week, what everybody doesn't even think about is how much revenue in sales and/or in profits are you losing from that week down? And, if you're going from cast to the better wrought alloy, you're talking about one week. If you're still going with the original less alloyed, thinner wrought tube, that's three times. Those savings can be much larger, depending on the facility, than just the material cost; it's just a few thousand dollars. I don't know how to evaluate how many tens of thousands or hundreds of thousands of dollars of lost production would be, but each shop has to consider that. They know the numbers; those are proprietary numbers that need to be considered.
With muffles, it's the same kind of analysis because you have the same alloys except muffles are not typically cast. But, let me give you an example. A lot of muffles operate at 2125 and, again, you use a 601 muffle. They're going to stay perfectly straight and flat at that temp for about six months. At that point, the typical shop will start seeing a little bit of roof sag and it will sag more and more and more. But there's plenty of room, so you can get a lot of sag before it starts interfering with the parts being conveyed. So, my general rule from the shops that I've seen, is that it can sag for about three times as long as it stays straight before the sagging is too great and has to be removed. Typically, it's about two years. With the better alloy, again, the case that I've seen was two years without any sagging and that was a higher temperature.
What we've done is we've actually gone to good customers who understand the concept and we work with them on developing case history. They log in when they put it in and the log in when they take it out. They have good records, number one.
Now, I'm talking predicted metal temperature based off the process temperature which could be more or less because it's estimated. But I know that the one that we looked at was at least 2200 on the metal temperature. And this was one of the really crazy ones because it was replacing a cast material of much higher quality cast material and the cast material was dead straight for a year-and-a-half, it would start to just creep a little, but if you're familiar with casting, there's not a lot of ductility in casting when it starts creeping maybe 3 or 4%, you don't have to worry about more creep; it ruptures! Then, the gas starts escaping and that's no good so they take it down. In this case, when you switch from the cast, the best wrought material was actually cheaper and it lasted longer and the particular customer would just change them every two years because they were still in cost savings mode. Based on my experience, I've predicted that they should be able to get at least six years on it. But, they're not willing to take that chance.
DG: The examples that you gave were the radiant tube and the muffles. I assume the same thing would be true, though, in retorts, for baskets or even fixturing systems, and things like that.
MG: Absolutely. I bring those two up because I have more good case histories.
DG: I assume the same would be somewhat true for fans, and things of that sort, if necessary, although you wouldn't be worrying so, so much about sagging and stuff like that. But anything, basically, I assume, metal.
MG: That's correct.
DG: How about measuring the life cycle of materials components? Any tips or tricks you've got for people on how exactly to do that and to get an accurate estimate?
MG: What we've done is we've actually gone to good customers who understand the concept and we work with them on developing case history. They log in when they put it in and the log in when they take it out. They have good records, number one. We've worked with others who've wanted it to work but they didn't do so good of a job tracking it. In one case, it was a much larger furnace where they had many radiant tubes and they were just working with a few of them. Personnel changed – one person didn't let the next person know about the trial and the identity got lost. So, we spent a lot of time for nothing. But, what we learned on that one is something real simple: You take a welder and you weld the alloy name somewhere on the tube and that's not going to wear away. Assuming you choose the right consumable, that weld is not going to go away.
DG: You already gave a couple of examples, but let me ask you this: How about a few concrete examples of where a more expensive material produced an overall more cost effective part? You already kind of gave us those back with the radiant tube, but are there any others that you've got along that line?
MG: The radiant tube is a great example. Muffles and retorts. We've been trying to work with some people on larger heat treating trays, but, again, there the task people have done a pretty good job, so we're trying to find a few people willing to go out on a limb and try something better.
Here, the concept is the idea of something lighter so that we don't look as much about the cost of the component. If you go with a lighter fixture, your furnace has a weight capacity and if you cut your weight 20-30%, you can put more parts on it and have more of your furnace BTUs going to heat treat parts instead of fixturing. When you're putting BTUs into parts, you're talking more profit per part.
DG: Right. You're not spending as much time, basically, using a basket as a heat sink, or something like that.
MG: Exactly. And, that's a concept that I introduced at one of the conferences about a year and a half ago. These things take time to percolate before they're accepted by people.
DG: Speaking of acceptance, let me ask you this question: Are these concepts that we've been talking about, the idea that sometimes less expensive is not better, is it widely accepted, do you think? I mean, do you think people understand it, generally speaking?
MG: Some people do. Not as much as I'd like to see! The other obstacle you're looking at is when you're looking at four years versus eight years and you look at some of the larger companies, you may have personnel turnover and one person doesn't want his 'replacement' to get all the credit. These are things that were learned the hard way. You have to get the right people to try it. A family-owned business is a perfect place.
I can give you another real good example on heat treating baskets where it made a difference. I'm going to give the name because I have done papers with him at a conference on this subject so I don't think it's taboo. I work with Solar Atmospheres on a basket for an extremely high temperature heat treating process that was slightly under 2300 degrees Fahrenheit. (We can say that because it's in the case history.) The first baskets that he used were your traditional Inconel 600 601 and they were supporting heavy parts. After five cycles, they had to cut all the sides off, hand straighten them (each of the sides) and weld it back together. That's timely. So, he went to another alloy, a better alloy, a competitor's alloy (HR120), and got ten cycles on it. He was very happy. Then, one of the people at their headquarters heard me give a talk on this new alloy that we had, our 602CA, which we trademark as RA602CA, and he got excited. He started asking me questions after the presentation and we eventually got kicked out of the room because it went well beyond the break; so we continued out in the hall as we walked to our company's booth and we talked. It took about ten to twelve months before they were ready to try it. We worked with their fabricator to get the material. They were up to forty-five cycles before they straightened it and there's a catch, though, to that. At forty-five cycles, they probably could've continued, but during the pandemic in 2020, when things were slow, they made a smart business decision that this would be a great time to do the straightening. I can't fault them, but it would have been nice to know just how many more. But, at forty-five versus ten, it is probably a similar cost at the time of manufacture. That's a no-brainer.
DG: So, we've covered some of the basics. We understand that it's not necessarily widely accepted so people should pay attention to some of these things that you've said. Are there any other economic factors that you think people aren't necessarily taking into consideration when they're doing material selection, besides the things we've talked about. Initial cost, life cycle, cost of replacement, and those types of things. Is there anything else that they ought to be thinking about?
As I mentioned in one of the cases, when there is significant down time to replace a part, you've got to consider how much money you're not bringing in because you're down for a week, or however long it is. This is often overlooked, as well.
MG: As I mentioned in one of the cases, when there is significant down time to replace a part, you've got to consider how much money you're not bringing in because you're down for a week, or however long it is. This is often overlooked, as well.
DG: To me, that's cost of replacement, because that's not just a hard replacement cost, but the downtime replacement, right?
MG: It's a little less obvious, though.
DG: Those are all good thoughts, Marc. When people go to do material selection, keep some of these things in mind. It's not just a matter of what the buyer, the purchaser guy, sees coming across his desk and comparing those two costs, let's talk about the material properties and longevity of the product and things of that sort.
I know that you, being with Rolled Alloys, you guys help customers, I imagine, pretty much continually on things like this. If people want to get in touch with you or Rolled Alloys, how is it best to do that?
MG: There are a couple of ways. The first way is my email: mglasser@rolledalloys.com. You can always ask me a question. On our website, there is a link to ask a metallurgist a question. I believe, you can also go www.metallurgical-help@rolledalloys.com and that will bring you to one of the metallurgists in my department and somebody will get an answer to you .
DG: Thank you very much, Marc. I appreciate your expertise. We'll hope it's helpful to the heat treat world.
MG: Doug, I thank you for having me as your guest and I look forward to more conversations with you.
Doug Glenn
Publisher Heat TreatToday
To find other Heat Treat Radio episodes, go to www.heattreattoday.com/radio and look in the list of Heat Treat Radio episodes listed.
How well do you know hardness processing? Can you draw the line where nitriding and ferritic nitrocarburizing (FNC) differ? In this Technical Tuesday feature, skim this straight forward data that has been assembled from information provided by four heat treat experts: Jason Orosz and Mark Hemsath at Nitrex, Thomas Wingens at WINGENS LLC – International Industry Consultancy, and Dan Herring, The Heat Treat Doctor at The HERRING GROUP, Inc.
Let us know what you think! What is the next comparison you'd like to see? What facts were you surprised by? Email Heat TreatDaily editor Bethany Leone at bethany@heattreattoday.com.
Nitriding
Descriptor
Ferritic Nitrocarburizing
480º-590C (896º-1094ºF) typical
Temperature Range
565º-590ºC (1049ºF-1094ºF) typical
Wrought and powder metallurgy materials including alloy steels (e.g., 4140), stainless steel (e.g., 304L, 420), tool steels (e.g., H11, H13) and special nitriding steels (e.g,, Nitralloy 135M, Nitralloy EZ) are typical examples. Many other steel grades are possible.
Materials Commonly Processed
Plain and medium carbon steels (e.g., 1015, 1018, 1045), alloy steels (e.g., 4140, 4340) and tool steels (e.g., H11, H13) are typical examples. Many other steels grades are possible.
Wear (as in abrasion resistance), bending, torsional and rolling contact, fatigue resistance, lubricity, and adhesive strength improvements.
Materials Commonly Processed: Why to Process Them with These Methods
Wear resistance, lubricity, fatigue, and corrosion resistance are primary benefits with improved fatigue strength and adhesive strength possible.
3-48 hours at temperature. May be up to 72 hours.
Relative Cycle Times
2-6 hours at temperature.
Pit retort furnaces and front load retort furnaces for gas nitriding, although bell retort furnaces have also been used.
Equipment Types Used for the Process
Pit retort furnaces and front load retort furnaces for gaseous ferritic nitrocarburizing. Bell retort furnaces have also been used.
Ammonia and nitrogen or ammonia and dissociated ammonia.
Atmospheres Used/Required
Ammonia and nitrogen and carbon-bearing gas such as CO2, CO, or endothermic gas.
Dies, gears, pump bodies, springs, gun barrels, shafts and pinions, pins, brake rotors and may other types of component parts produced from bar, plate, rod, forgings and castings formed by stampings, machining, rolling, forging, casting, etc.
Typical Parts Processed
Wear plates, washers, clutch plates, gas pistons, brake pistons, brake rotors, barrels, slides, differential cases and other types of component parts produced from bar, plate, rod, etc., and formed by stampings, rolling, machining, casting, etc.
Cost is often higher for gas nitriding as opposed to other case hardening processes (including FNC) based on the type of component parts run. In many cases, cost is a function of the longer cycle time and/or more labor involved.
Relative Cost Per Unit
Cost is often lower than many other case hardening processes (including gas nitriding) based on the type(s) of component parts run. In many cases, cost is a function of a shorter cycle time and/or less labor involved.
Basic specifications are easily achieved with good equipment and/or controls; difficulty increases when attempting to produce specialized layer compositions/phases.
Ease of Use/Control
Basic specifications are easily achieved with good equipment and/or controls; difficulty increases when attempting to produce specialized layer compositions/phases. Hardware/control requirements are more complicated than for nitriding when controlling for carbon potential.
It can range from very simple to medium-high depending on application.
Relative Expertise Necessary to Perform
Medium-high depending on the application. The user will want to look for clean parts, a good loading system, and PLC controlled cycle.
Aqueous (clean chemistry) including rinse/dry, vapor degreasing (clean chemistry).
Cleaning Requirements
Aqueous (clean chemistry) including rinse/dry, vapor degreasing (clean chemistry).
Time, temperature, gas flow, nitriding potential (Kn) and/or percent dissociation, hydrogen sensors.
Controls
Time, temperature, gas flow, nitriding potential (Kn), carbon potential (Kc) and oxygen potential (Ko). Hydrogen sensor and oxygen (carburizing) sensor may be used.
electric and gas-fired equipment
Fuel Source
electric and gas-fired equipment
Hardness (surface, core), case depth determination (via microhardness – typically core hardness + 50 HV), microstructure (compound and diffusion zone depths), composition, core structure, presence of absence of nitride networking (aka nitride needles), and the presence or absence of cracking or spalling of the case.
Testing Required
Hardness (surface, core), case depth determination (via microhardness – typically core hardness + 50 HV), microstructure (compound and diffusion zone depths), composition, core structure, porosity (type and depth), and the presence or absence of cracking or spalling of the case.
Warm wall plasma nitriding, as well as advances in controls, sensors, temperature uniformity, and reduced gas volumes.
Latest Advances
Black oxide, hydrogen sensors, and fast cooling techniques as well as advances in controls, sensors, and temperature uniformity.
(1) simple equipment, (2) can offer beneficial tribological changes part/metal, (3) performed after part machining, (4) little-to-no distortion.
Pros (Strengths)
(1) fast, cheap, repeatable results, (2) excellent corrosion resistance, especially with (black) oxide, (3) performed after part machining, (4) minimal distortion/almost distortion free
(1) long cycle time, sometimes a multi-day process if deep case is required, (2) effective pre-cleaning required, (3) weldability becomes reduced, (4) ammonia is used, (5) embrittlement with too much white layer.
Cons (Weaknesses)
(1) Focused on part surface, mainly with inexpensive materials, (2) effective pre-cleaning required, (3) weldability becomes reduced, (4) ammonia is sometimes a concern.
Doug Glenn, publisher of Heat TreatToday, moderates a panel of 5 experts who address questions about the next 5-10 years in the heat treat industry. What are the trends and what should you prepare for. Experts include Peter Sherwin, Eurotherm by Schneider Electric; Janusz Kowaleski, Ipsen Group; Andrew Bassett, Aerospace Testing & Pyrometry; and Dan Herring, the Heat Treat Doctor from The HERRING GROUP, Inc.
You can view this special video edition of Heat Treat Radio by clicking the button below.
Heat TreatToday publisher Doug Glenn and James Dean of Plastometrex discuss indentation plastometry, a new technique for obtaining important mechanical property values for a wide variety of materials. The company’s equipment is just barely 6-months old and is already finding its way into heat treat applications in North America.
Below, you can either listen to the podcast by clicking on the audio play button, or you can read an edited transcript.
The following transcript has been edited for your reading enjoyment.
DG: Today, we're going a bit international. We're going to have a conversation with Mr. James Dean from Plastometrex in the UK, which is obviously a far spell from Pittsburgh, where I'm located. James, welcome to Heat Treat Radio. We're looking forward to talking with you.
JD: Thanks, Doug, it's nice to be here.
DG: We want to talk about materials characterization, testing and things of that sort. We'll get into, specifically, what part of that in just a bit. But first, James, if you don't mind, briefly, let people know who you are, the qualifications you have to be talking about the topic that we will be hitting on, and about your history in the heat treat industry or in the materials characterization industry.
JD: Quick background: I'm a materials scientist from the UK. I first studied materials as a young undergraduate at Imperial College in London. That was way back in the year 2000. I subsequently went on to do a PhD in Cambridge, also in materials science. It was during that period when I really first became interested in the mechanical behavior of materials, particularly strength characteristics and the relationship between those strength characteristics and underlying microstructural features. In fact, one vivid memory that I have from an undergraduate laboratory class was measuring Vickers hardness numbers on age hardening aluminum copper alloys and monitoring the changes that occurred with different heat treatment times. That all struck me as being quite powerful because it meant that we could tune mechanical properties. Up until that point, I hadn't fully appreciated that that was possible.
What's a little more unfortunate is that I've also since learned that if we want to achieve a particular characteristic, high strength for example, we often have to do so at the expense of another, usually the ductility. I guess that's why material scientists all over the world continue to look for new compositions, new alloy systems, even novel heat treatments that offer mechanical performance improvements that, perhaps, haven't yet been realized. My involvement in this industry is driven simply by my interest in these things, which is why I feel extremely lucky to be leading a company like Plastometrex.
DG: Tell us a bit about the company. You're the CEO there. As I mentioned earlier, you're located in Cambridge, UK. Tell us about the company, its history and about the products and things of that sort.
JD: Plastometrex is a company that develops novel mechanical testing systems that are powered by advanced software tools. By advanced, what I really mean is state of the art modeling methods, things like finite-element analysis, optimization algorithms and also, forgive the buzz words but, machine learning tools, as well. These are needed because our machines measure stress strain curves and metal strength parameters from quick and simple indentation tests.
There is some justification to say that people have been indenting materials for centuries and, of course, that is true. But people have been doing this simply to measure hardness numbers, predominantly, at least. We might argue that anybody that understands a little bit about hardness testing probably also understands that hardness numbers are not fundamental material properties. They would understand that a material's hardness number actually changes if you change the shape of the indenter that you use or if you change the load that you apply.
Hardness numbers can only really be used in a semiquantitative way to rank materials. They can't be used in a design calculation or in a finite-element analysis. So, to use them as proxies for strength, which is often done, can, in fact, be potentially dangerous. I would go on to say that, unfortunately, hardness numbers are often accorded a much higher significance than they really deserve. My own view is that it is much better to have access to fundamental strength characteristics which is why we've been spending our time developing these new machines and their associated software packages.
So, to wrap up the question, the technique is called indentation plastometry and it was developed over a 10 – 12 year period of research, led mostly by Professor Bill Clyne and his research group in Cambridge. On the back of that, we established Plastometrex in late 2018 to commercialize the technology.
DG: You're saying the company, Plastometrex, was established in 2018. So, you're about 3 years into this. Are you fairly successful so far? I mean, are you happy with the progress?
JD: I would say that we're reasonably happy with our progress so far. Of course, like a lot of companies, we're just coming out of this rather difficult period because of Covid. What that means, for a company like ours, which I guess you could still class as a start-up, is that it's just much harder to sell equipment.
What we're finding right now is that lots of companies rationalized their organizations in various different ways. One of the first things that companies seem to have done, which is quite understandable, is put restrictions on their CapEx spending. That's something that we, like most companies, have to deal with at the moment.
But, notwithstanding that, I would say we still make good progress with monies to secure quite substantial amounts of investment. One of our leading investors is Element Materials Technology. They're one of the world's leading providers of testing inspection certification services. We're still employing more people. At this stage, we're launching new initiatives and we are selling machines, despite the current climate. Our trajectory looks quite good right now.
DG: Where are you selling, primarily? Is it mostly Europe?
JD: It's mostly Europe, at the moment. We have sold one of our machines, actually, to Worcester Polytechnique Institute in North America. We're actually having conversations right now, I won't disclose them, with other North American universities who have expressed an interest in technologies like ours.
DG: Good. It's good to see a young company doing well even in the midst of Covid, so congratulations on that.
Broadly speaking, your company is dealing with materials characterization testing. The equipment you produce: what properties is it, in fact, intended to characterize? You've already hit on this a little bit- stress, strain, etc. Maybe briefly explain each of those properties for those who might not know what the difference of those things are. A quick “materials 101.”
JD: The very quick answer to your question, Doug, is that we are measuring plasticity characteristics or strength characteristics. They're often best captured, or best represented, in the form of the stress strain curve.
Now, stress strain curve of material is really quite important since from it you can deduce important features like the stiffness of a material. But then there are other features, such as those I've described that relate to the plasticity characteristics. These are things, like the yield stress of the material, which is the stress at which the material starts to plastically deform or, i.e., permanently change its shape.
You can also view the hardening behavior as the material continues to strain, which is often quite important. And, you can also extract from the stress strain curves things, like an ultimate tensile strength or a fracture strength, and these things can be used in things like design calculations.
From the stress strain curve you can also extract a ductility value, which is a nominal strength fracture for those people in the know. But, as with hardness numbers, the ductility value is also not a fundamental material property and this is often not understood. The ductility value actually changes depending on the test geometry that you use. That's an important thing to understand because people often use the ductility in things like engineering critical assessments not fully understanding that that value can be different depending on the test that you did.
I think the important message here is indentation plastometry can be used to measure things like the yield stress, to measure the uniform elongation strength, to measure the ultimate tensile strength of the material. But, our technique can also be used, if you want to, to calculate things like the Vickers and the Brinell hardness numbers, as well. But, the limitations around hardness numbers that I've already outlined still apply.
DG: Your product is basically offering a new way of doing some of these tests. Basically, it almost looks like just a hardness test because you're doing the indentation, but you're getting a heck of a lot more out of it. Maybe, again, just 101, how have these tests been done in the past and what is the method that you've been developing over the past 3 years? How does that differ and what is the benefit?
JD: The current gold standard for mechanical testing is the uniaxial tensile test. To us, at least, that is another mechanical test that hasn't fundamentally changed for almost a century, actually. In principal, it is a rather simple test where you take a test specimen in the form of a testing coupon and you stretch it (or strain it, to use the proper term), and you do that until it breaks. If you monitor the forces in the displacements during the test, it's very easy to calculate the stresses and strains within the sample. But, there are a number of problems with this type of testing machine.
The first is that you need to have access to quite a lot of the material that you want to test because the test specimens are usually quite large, often in the centimeter dimension range. That also means that the material that you want to test needs to be machinable, and not all materials are; I'm referring mostly to metals here. In fact, some are actually quite difficult to machine so that this process of machining test coupons can be quite a cumbersome one. Often quite time consuming, too, especially if you need to outsource these procedures.
The test itself also requires access to a large, often very expensive, universal test machine, and, in addition, a suitably trained technician, as well. There can be further problems with things like specimen gripping, alignment of the specimen, machine compliance, and other things like that.
Whereas, and of course I'm biased, a machine like the indentation plastometer, really combines the very best attributes of hardness testing, which is speed, ease and simplicity of testing, with the very best attributes of tensile testing, which is acquisition and access to forced stress strain curves.
I would add to that, as well, that with a machine like ours, you can test real components and you can map spacial variations in properties across surfaces, such as those, for example, that might exist across a weld. Again, in summary, we think you get the best of both worlds with our machine and, in some cases, even things that are better than other machines.
DG: You may have already stated this a little bit, but briefly: indentation plastometry is basically taking an indentation to be able to test, not just hardness or not even necessarily hardness, but the deformation or the strain of material. Do you have to know the microstructure of the material when you're doing these tests?
JD: That's a good question. In principle, no. If we were to dig deep into the mechanics of what's going on within our system and our software package, you'd come to recognize that it's, from a mathematical point of view at least, insensitive to microsctructural features. There is a numerical method underlying this – a finite-element analysis – therefore, treating this as a continuum system doesn't take account explicitly of the microstructure.
When you're doing the test, it's actually helpful to know something about the microstructure simply because our technology is all about extracting bulk mechanical behavior engineering properties. Therefore, when we do our indentation test, it is important that we are indenting a representative volume of the material.
It is important that we are capturing all of the microstructural features that give rise to the behavior you would measure in a microscopic stress strain test. Otherwise, you can't pull out those bulk, core engineering properties, and therefore, the scale on which you do the indent is important. Your indenter has to be large relative to the scale of the microstructure. So, it's only at that level that you need to understand or know anything about the microstructure.
DG: This test is a nondestructive test, right? You said you can actually test live materials, correct?
JD: Yes.
DG: You don't have to destroy them, you don't have to machine them, you don't have to make them into something you can rip apart, right?
JD: Right.
DG: Is there a limitation on the size of the product that you can test? Do you have to put this thing into a machine to clamp it down to do the indentation?
JD: Yes. There are some limitations. I'll come back to those in a second. I just want to address the first point. It wasn't a question, but you actually referenced it, so I'm going to pick up on it, and it's about whether this test is nondestructive or not.
It's an interesting question. I think, really, it's a matter of perspective, or sometimes, a matter of even industry. We don't destroy test samples in the same way you do during a normal tensile test. But, we do create small indents in the surface of the specimen. Whether that can be regarded as destructive is really open to interpretation. Our colleagues in the aerospace industry probably would be comfortable testing a turbine blade and then putting it back into service even if the indent is relatively small. So, on that basis, they might consider the test to be a destructive one. But, for many other applications, we, and others actually, would regard our test as a nondestructive one and, indeed, that is often how we pitch it.
Then, to the second question which is about limitations on size. . .
DG: Yes, size, geometry, shape, or anything of that sort.
JD: There are no restrictions on shape, per se. It's important that the specimen has two parallel sides. When you put in on the plinth, under which when you do the testing, when you come down normal to that surface with the indenter, you want them to be as flat as possible. You can accommodate small inclines up to 2-3 degrees, but ideally they would be parallel. So, that's one constraint.
In terms of total size, if you look at a bench top machine, (and anybody visiting our website would be able to see it), it's got sort of like a window, a cavity, where you can put your specimens into which has got a width of about 20 cm, height of about 7 cm and a depth which is also probably about 20 cm, as well. That is what is governing/dictating the maximum size of sample you can put in there, at the moment.
In terms of the other direction, how small can you go, we advised people not to indent anything that has lateral dimensions less than about 5 x 5 mm and that is because if you start to indent close to edges, you can get edge effects and therefore in our software package, behind the scenes, the modeling assumptions that we impose start to break down.
In addition to that, in terms of the sample thickness, we typically impose a minimum height of about 2 mm. Then again, that is because, in our underlying software package, the modeling assumptions assume that what you're indenting is essentially semi infinite in size and if you indent thin samples, that assumption breaks down too. That's what is driving those constraints on sample size.
DG: And, being able to run a test on a spherical object is not a problem as long as you can get it flat, I mean, like pipe tube and that type of stuff?
JD: Pipes are interesting, actually. One of the things we're working on right now as a company is an in-field testing kit, or portable detection plastometer. Our immediate focus is on the pipeline materials. In fact, you might know this, there is some new legislation in North America called the Gas Mega Rule which is now mandating that pipeline operators inspect their pipes, I think it's probably every one mile into this. One of the tests that they need to do is a strength test.
There's a big opportunity out there, potentially, for the testing of pipe materials. A technology like ours is something that could support and enable that. But then, coming back to your question about indenting a surface that is curved, which is what this really relates to. And that is simply, again, a matter of scale. If it's got extremely high curvature and you come down with an indenter such that the curvature is large with respect to indenter size, then you can now have problems. If the curvature is small relative to the scale of the indent, then it's okay; i.e., if you come down and it still looks like a flat surface, it's the indenter because of the differences in scale, then you're okay.
DG: And, I think you said the 2-3 degree the tolerance which would come into play there.
JD: Indeed.
DG: Most anybody that's going to buy this equipment is going to say, “OK, what's in it for me? Why should I buy this thing as opposed to going the normal route, or things of that sort?” Talk to us a little bit about the overall expense, overall experience with your equipment. Why would it be something that people would pick up?
JD: From an experience point of view, I think one of our key objectives while developing the technology and, indeed, the supporting software, has been to ensure that the experience of using the system is a smooth one. We've attempted to minimize the level of interaction to these it needs to have with the machine and the software and also to try to maximize the degree of automation. I think that we've been able to strike the right balance. I think the workflow is simple and intuitive. And, importantly, we present the results in a format that the users would recognize if they've previously done conventional mechanical testing.
I think one of the key attributes, if you like, one of the key salable attributes of our system, is that you can measure full stress strength strain curves in just a few minutes, 2 – 3 minutes, so almost in real time. When you're doing this thing in real time, it's potentially transformative for lots of businesses in lots of different ways because it unlocks that materials testing bottleneck that lots of companies are already familiar with. I don't like the term, but the value proposition, if you like, is speed of testing, ease of testing and simplicity of testing. That's where you're going to derive the most value from a machine like ours.
DG: Do you have any examples of where somebody has used this? You don't need to mention names, of course, I'm not asking for company names, but maybe an industry where somebody's been able to kind of move their testing into real time testing? And if you don't, that's also okay.
JD: I can give you a couple of examples which we can disclose. We've got some people using our machine for high thru port testing and combinatorial analysis with things like additively manufactured metals. That is basically where companies that are using additively manufactured systems are very keen to understand how changes in process parameters and changes in alloy composition and changes in powder type and powder size distribution, what effect that has on the mechanical properties.
If you want to do this using conventional systems, you've got to print tensile specimens or other types of bonds, and they you've got to print them and test them. This is quite cumbersome. Whereas, with our machine, you can just print a small cube or small disc or something like that, and then you can immediately indent it and get stress strength curves. You can do, essentially, rapid design exploration and rapid process optimization.
This is not just specific to end processes. Wherever you've got all the types of thermomechanical processes taking place to develop or design the metals and you need to characterize the corresponding strength characteristics and you want to do it quickly, then you need a machine like ours.
DG: They wouldn't even need to print the actual part; they'd print a suitably large enough cube, test it, and then you'll know.
JD: Absolutely. And that cube, as I've described, could be quite small, it might just be 1 cm cubed in volume and that would be sufficient. So, actually, the cost of doing this test comes down, as well, because you're not printing lots of material.
We're working with additive manufactured companies right now that are validating the technology. We're having some of these companies print material for us and it's extremely expensive unfortunately and it's just a process that we have to go through at the moment to prove out the technology. They can see the benefit themselves of being able to rapidly characterize the strength of their materials.
DG: Do you want to address, at all, as far as overall lifetime expense investment in a product like yours as opposed to other testing methods? We talked about workflow, ease of use, ease of reporting and things of that sort. Any comments on lifetime costs of use?
JD: Yes, I can say a few things. First off, our machines typically retail at prices which are comparable to a low end universal mechanical test machine, mid-range for hardness test machines, so sort of right in the middle there. Although, as I've said before, I think our machine benefits from having the best attributes involved. It is a robust machine, it's just doing indentation tests, so the longevity and the robustness is good and strong.
There are very few aftermarket parts that you might, conceivably, want to buy to bolt on. You don't need suitably trained technicians either with backgrounds in mechanical testing or material science; you can press the button and run it. The lifetime costs, we think, are substantially better than a conventional tensile test machine. If people want to talk a bit more about the commercial aspect of these machines, they, by all means, can get in touch.
It might be worth mentioning, it's not necessary to buy our machines. We do have leasing agreements specifically because of these CapEx restrictions that we're seeing out there in market right now, but also because of a certainty you can anyway. If these go on to operational expenses, then there are certain tax advantages, as well, to doing that.
DG: Types of companies that would find this to be really helpful. In other words, are you seeing that a certain industry or a certain type of company are interested in your product, or an industry that should be that is not yet?
JD: A good question. We've been extremely surprised, actually, at the level of traction we've been able to generate so far. We officially launched our machine in November of last year, so we're only 4 or 5 months since the launch. We're already talking to probably 50 or 60 companies right now, including some major, major tier 1 companies across the world.
I think one of the great things about materials testing is that it is not set or industry specific. Almost all industries need access to the strength of their materials in order to design new products, for example, or to ensure that the materials or products that they produce are safe to operate and fit for purpose. At the moment, we're getting a lot of interest from metal producing companies, processing companies from the additive manufacturing community which, traditionally, have been quite difficult to measure the strength of their materials, from aerospace companies to automotive companies to companies engaged in things like failure analysis and also from universities and research institutes, too.
We're really seeing an interest from a very broad range of organizations and I think that is reflective of what I said in the beginning of this question which is that materials testing is not sector or industry specific, it's kind of ubiquitous of all those industries.
DG: What are you most excited about with this company? You're, what, 6 months into it maybe as far as actual product out there? What puts a smile on your face?
JD: That's a good question. There are a couple of things that put a smile on my face. One, I really enjoy working with the people that I've got on my team, who are as enthusiastic and as motivated as me to see this company do well. And, I also really enjoy talking to the wide range of customers, because what I see when we talk, is them saying, “Gosh, if we would have known about this 5 years ago, we'd be already using it.” or they say, “This is fantastic. This is exactly what we've been looking for and it can solve this problem and that problem.” Then, they start coming to me and saying, “Can you also change something up so that we can do this or we can do that?”
So, there's always new potential opportunities arising because of it. That really excites me, because what it points to is additional opportunities for plastometry.
DG: What do you worry about? What keeps you up at night?
JD: I guess, the immediate concern right now is what the recovery post Covid looks like, especially in certain industries like aerospace which, in ordinary times, would have been an ideal market for a technology like ours. That's the type of thing that makes me worry. So, we're keeping a very close eye on what the recovery looks like, not just here in the UK, but also abroad.
The other thing that, I wouldn't so much say worries me, but it is something that we're thinking very hard about, is the standardization methodology, as well. If you want to get a technology like ours used broadly across all industries, then one thing that crops up a lot is, Is it certified? Is there a testing standard? At the moment, there isn't.
We are compliant with a couple of testing standards around instrumented indentation testing. We're also working, right now, with the National Physical Laboratory in the UK, which is, I guess, our equivalent of your NIST (National Institute of Standards and Technology). They are working with us, right now, as a precursor to supporting our efforts towards standardizing our test technology. It's a 3 – 5 year program, but I think if we can tread that long path properly and get the test methodology certified, then, again, additional opportunities will open to us in those more conservative industries.
DG: Do you have a presence in North America, or do you have a way of dealing with customers in North America?
JD: We have no formal way of doing this, and at the moment, it's manageable because we're not getting hundreds of requests every day. We are shipping machines to North America. We are managing it internally by ourselves, at the moment. One of the things that we do have in our back pocket, so to speak, is our relationship with Element, one of our leading investors. We have a huge North American presence and they can certainly support us where needed, if, for example, we need to set up a base in North America or engage with distributors in North America or something like that.
DG: We talked before we turned the recording button on about how to properly pronounce your company; it's not plastometrics, it's Plastometrex. Where would people go if they want to find out more? If you're comfortable, James, you can give out whatever personal type of information, if you want your cellphone out there or email or whatever, feel free to do that, as well as your website.
JD: The first place we encourage people to visit is our website, and that is www.plastometrex.com and there is information there about our machine, about its capabilities, there are some FAQs, there are lots of technical articles sort of describing the underlying science, and there are research publications. It's a really good source of information for people.
One of the other places I point people to is our LinkedIn channel. We have a very active presence on LinkedIn where we're constantly pushing our material- some technical, some promotional, some lighthearted, some serious. It's a really good place to engage with us. We've got lots of educational content going out, as well. And, of course, people can reach out to me directly at my LinkedIn by searching for James Dean Plastometrex. They are the three best ways, I would say.
Doug Glenn
Publisher Heat TreatToday
To find other Heat Treat Radio episodes, go to www.heattreattoday.com/radio and look in the list of Heat Treat Radio episodes listed.
Heat TreatToday publisher Doug Glenn discusses hot isostatic pressing with Cliff Orcutt of American Isostatic Presses, Inc. Learn about the revolution that is occurring in the heat treat industry and how it is being used across various manufacturing industries
Below, you can either listen to the podcast by clicking on the audio play button, or you can read an edited transcript.
The following transcript has been edited for your reading enjoyment.
Doug Glenn (DG): First off, Cliff, I want to just welcome you to Heat Treat Radio. Welcome!
Cliff Orcutt (CO): Thank you.
DG: If you don't mind, let's give our listeners just a brief background about you.
CO: It's been 43 quick years in the industry. I, actually, did start as a child. My father was one of the original people at Battelle where it was patented in the '50s, so, I grew up under that. Right out of school, I went to work for his company, after he and another gentleman left Battelle, Mike Conaway, and they formed Conaway Pressure Systems. By the time I was 20, I had already installed 10 HIP units around the world and helped design and build the Mini Hipper.
I was involved in 1978 in moving the world's largest HIP unit from Battelle to Crucible Steel in Pittsburgh, which is now ATI. Also, in 1979/80, we installed the very large system for Babcock and Wilcox at the Naval Nuclear Fuel Division in Lynchburg, VA. Both of those units, 40 years later, are still running.
I'm also past president of the Advanced Materials Powder Association, part of MPIF, and I was also a director of their Isostatic Pressing Association. I am currently the chairman of the International HIP Committee. We put on the triennial HIP conference every 3 years.
DG: Is that part of APMI?
CO: It's actually its own group. It was formed by all of the people in HIP around the world, in Europe and Japan and the United States back in, maybe, 1983 or so.
DG: What's the name of the organization?
CO: It's called the International HIP Committee. It's kind of a loose organization which the only thing that we do is put on this conference and we bring in speakers from around the world and promote HIP technology, basically. Our last one was in Sydney, Australia in 2017. We were supposed to have one in October 2020 and now it's pushed until September of 2021.
DG: Where will that be?
CO: It's going to be in Columbus, Ohio because that was the original founding city. Every other conference, we move to the United States, Europe or Japan. So, it's coming back to the US. I'm in charge of it. We have some other good people on the board, including Mike Conaway, who was one of the original Battelle people. Victor Samarov is on the board helping us with the meeting, programming and so forth. People can visit www.hip2020.org to see information on that.
DG: I got you a little distracted on that. Keep going with your background.
CO: Personally, in these 43 years, I've installed over 200 units, hands on. I've flown about 5 million miles, I've been to 38 countries; you name it, I've been there, good ones and bad ones. In my early years, when my father started this company, they pulled about 6 people out of Battelle and they were, basically, my teachers. So, instead of going to educational school, I went to HIP school. We had some of the top people: Roger Pinney, Hugh Hanes, Don Woesner, Gary Felton and another gentleman, Bob Tavnner, all came out of there.
In 1979, my father passed away, and his company then sold to ASEA who then became ABB who then became ABB Flow and then they became Quintus now. That's how they have a location in Columbus, as well.
A couple of people, including Bob Tavnner, left and formed International Pressure Service. That was in 1983. They hired me as operations manager, and we grew to be a force to be reckoned with and the Japanese then bought us. At that time, Rajendra Persaud, or Reggie we call him, left and formed AIP (American Isostatic Presses) and I said, “Hey, Reggie, let's have a two person company again rather than two one-person companies.” That was 1992 and so, 28 years later, now we're a force to be reckoned with again.
DG: Tell us a little about AIP.
CO: American Isostatic Presses, when the Japanese bought us, we had a lot of technology and a lot of good people. Then they hired a new CEO and he decided he didn't want to continue building HIP units, he wanted to do something else. So, Reggie formed AIP and I joined him and we pulled 5 other people back from ITS. We sold our first big job in 1994 to Horus in Singapore, a multimillion dollar job, and took off from there and haven't looked back. We started on a shoestring, no venture capitalists, no dollars, and now we have 4 buildings and locations around the globe.
"We're just a high tech blacksmith, that's all it is. Instead of hitting something with a hammer, we're using gas pressure to squeeze on it."
DG: How many units do you think you guys have installed since 1994?
CO: As AIP, around 150. It's snowballing. In the last 5 years, we've sold 5 big units. Up until that time we were mainly mid and small. We had orders for some big ones but, unfortunately, we couldn't get export licenses for them. The technology that grew out of Battelle was based on nuclear fuel rods for the submarines. Admiral Rickover wanted to extend the life of the sub, so it was protected for quite some time. And then they also had missile nose cone technologies it was used for and that's still what they're protecting it for is missile nose cones.
We had some orders in the late '90s early 2000 through China for large equipment and we were denied. Then we were denied in India, so we kind of just got stuck with the smaller to mid-size units. Here recently, it's starting to expand. Things are loosening up a little bit.
DG: AIP today is selling not only in North America, obviously, but you're pretty much selling around the world, anywhere where it is legal to sell, you'll do it.
CO: Yes, if we can get an export license, we will put it in. Some of the rules have relaxed a little bit, and, with some countries, we're more friendly with them now.
DG: I think a lot of our listeners are probably not going to be as familiar with HIPing, hot isostatic pressing, as other more common “heat treat operations” like carburizing, hardening, annealing and that type of thing. Take us back, class 101: What is HIPing?
CO: We're just a high tech blacksmith, that's all it is. Instead of hitting something with a hammer, we're using gas pressure to squeeze on it. We heat it up hot, we put pressure on it, and we're basically densifying it, making it more dense, and getting rid of imperfections in the metal.
A lot of what's done is castings. When you have a casting, the metal is hot, so it's expanded. When it cools, it cools from the outside in, so it freezes on the outside first and then the center starts to shrink. It creates internal porosity. Most of that porosity is thermal shrinking which is a void. So, you put it back in our heat treatment, apply pressure to it and you get rid of the voids that are left. You make the casting dense and better grain structure and more homogenous. It increases fatigue in property strength. That's the number one use of it right now.
Second is probably powder metallurgy where you take powder metals and you can blend powders and you can start with different grain sizes and different materials. You put them in a container because the gas would go through the container if you didn't have something around it. So, you squeeze on the container and it densifies whatever is inside of it and you make a solid part. For example, a lot of powder metallurgy billets which are then used for extruding into other products or rolls and different things. We do a lot of pump bodies and valves for deep sea work, extruder barrels, you can bond things; there are a whole lot of applications.
DG: The two things I understand with HIPing are high temperature and high pressure. Give us a sense of high temperature. What does that mean? Is it hotter than a typical heat treat operation? And how about the pressures? Give us a sense of what the pressures are looking like.
CO: A lot of people are familiar with sintering. That's where you just take the metal up, you sinter it and the grains merge together by melding and attractive forces. What we're doing is: we're not taking it up to those high temperatures to where the part actually is molten or melting, we're taking them up below that and applying pressure. Because of the pressure, we're basically pressurize sintering; we're adding force to make it sinter faster or better or at lower temperatures.
Usually, it's about 150 C degree less than sintering temperature. Again, it depends on the process of what we're trying to do with it. Typically, most parts are done around 15,000, some parts 30,000. Here, at AIP, we actually have test units up to 60,000 PSI and we've actually built 100,000 PSI HIP units. You're above the yield strength of some of the metals you're using. Most of the majority, again, in like castings, titaniums around 970, steels around 1225, but we go up to 2200 C for some things, even higher for like half-in carbide with people pushing it to 2300. It's pretty hot, a lot of pressure. Unfortunately, high temperature and high pressure costs money. You want to use the lowest pressure and the lowest temperature you can get by with, but sometimes you can't.
DG: It's harder, I would imagine. The way I've always heard it said is that the hotter it is, the more difficult it is to keep, let's say, that cylinder container that you're talking about. If it becomes hotter, it's harder to keep it together. I would guess you're right, when you've got higher temperatures, things tend to blow apart easier?
CO: Not so much. The temperature is contained in the middle of the pressure vessel, so you've got plenty of insulation around it and you keep your container cool. The goal there, in a HIP unit, because it's the expensive piece of item, you want maximize your work zone, that's where you have to have good engineering to make sure you do keep the container cool.
DG: Are most of those units water cooled jackets, or are they cold wall?
CO: They're almost all hot wall, but some of them are cooled internally and some of them are cooled externally. You still have loss to the metal, whether it's internal or external cooled, but internal gives you faster cooling than the external.
The big advantage of HIPing is, like with some materials like titanium, you can eliminate a lot of machining. Making chip that you can't really reuse real easy makes a lot of economic sense. Titanium is a very high melting temperature, so you can't take those chips and melt them cheaply. Aluminum, you can. A lot of aluminum, people can't afford to HIP it because you can just recast it.
HIP is an expense process. The equipment is expense. It uses argon gas. Swinging a hammer is cheap, but using gas pressure, it's so compressible, that you have to put a lot in. You can reclaim some, but the cost is still high. You're talking medical, aerospace and military, basically. Forty years ago, I thought every car would have HIP pistons. It's just not going to happen. They can't afford it. I do see Edelbrock and Trickflow both have HIPed aluminum race heads, though. If you get into where you have the economy of doing something like that, you can apply it. You're definitely going to get a better product, it's just price versus performance.
Watch an "oldie but goodie" on what HIP is.
DG: As far as why people want to do the HIPing, I guess, primarily, it's an elimination of, let's say, defects or inclusions or whatever, either cast parts or powder metal parts, you're increasing fatigue strength, and things of that sort.
Are there any other major reasons why people want to HIP?
CO: Well, there are some things you can't make other ways. In other words, it's like water and oil, you can't mix them very well and some metals you can't melt them and just make a molten bucket and pour it. In HIP, since you're starting with powders that are solid, you can blend things like graphite powder and steel. You couldn't blend them very well in a molten state, but in here, you can. And, you can squeeze it to solid, you can get interlocking and bonding and diffusion bonding materials that you couldn't otherwise. So, you can make things you couldn't make any other way.
Also, you can eliminate machining. For instance, you're making a titanium fitting that has a lot of holes on the inside, it might even be curved and really hard to drill, but you can lay it up and do powder metallurgy around it and make shapes that you couldn't make otherwise. A lot of parts are pressed and sintered for years, for instance, for transmissions. Something like that is real easy because it's a small disc and it's not very long. But, if you're trying to make a real long part that is a strange shape, you can't just press and sinter it. You can do it from HIPing. You can do big shapes that you couldn't get enough force on or you can't fit into a press dye. You can do big shapes that you couldn't get enough force on or you can't fit into a press dye. It opens up a lot of options. A missile nose cone, for instance. There is just almost no way to press and sinter a cone, but with HIPing you can make that shape and you can make it very uniform. There's really no other way to do it.
DG: I think that is one of the benefits of HIPing, from what I understand, it is absolutely equal pressure on all parts when you increase the pressure. It's not like you're only pushing on one part, like with a forge press, or something like that – equal pressure all round.
CO: Yes. And it gives you uniform density throughout the part, which is very difficult.
DG: HIPing is primarily used on castings, powder metal and things of that sort, helps us get a very clean part, if you will, to eliminate inclusions, and minimize the porosity.
You may have mentioned this before, but the actual history of HIPing. It started at Battelle?
CO: It started at Battelle [Memorial Institute], I think in '55 or '56. Again, for the nuclear fuel rods for cladding of the fuel rod. Four people were involved in the patent, two of them, Ed Hodge and Stan Paprocki, "the two others on the patent were Henry Saller and Russell Dayton" I worked for both of them over my years. It grew out of Battelle and then in 1975 is when my father and Mike Conaway left and formed Conaway Pressure Systems. That was kind of like the beginning of the commercialization of it. There were some other companies, like Autoclave Engineers, that were building high pressure equipment, but they weren't really offering packaged HIP units. Conaway Pressure, CPSI we called it, was really the origination of commercial HIPs as we know it.
DG: You hit on this a little bit, but I want to make sure that we're clear on it. You mentioned the industries that are using it, but let's just review that real quickly, and maybe if you can give any example of parts. You said, they've got to be higher value parts because the process is expensive, so we're looking at aerospace, medical and that type of thing. What primarily, at least in those two industries, and other industries if you want to list, are the parts being run?
We’re seeing a lot of application now in ceramics. We see pump plungers and ceramic bearings. Here, at AIP, we do a lot of military work for armor, boron carbides, spinell (21:03), things that are really hard, ceramics. . . You want them perfect because if they have a defect in it, that’s a starting point for a crack. A lot of brakes for jets and fighter jets.
CO: A lot of extruder barrels. What happens is you can use a solid steel chunk of metal for the barrel portion but then you can HIP or diffusion-bond powders on the inside of that barrel that might be very expensive. If you're doing something like a crane or something where the teeth are outside, you can weld on. A lot of times they'll weld on hard brittle materials that help you dig things with a digger. But on an extruder barrel, it's on the inside, it's internal; it's very hard to coat down on the inside. So, we can actually bond those powders to the inside of extruder barrels.
Another big application is sputtering targets. I don't know if you're familiar with sputtering targets, but they're basically sacrificial material that you plate onto other materials. The target is just something that is being hit with an electron beam inside a vacuum furnace. It creates a vapor and by charging the different particles you can attract them and plate things out. All of your mirrored windows, all of your hard drives, all of your CDs and DVDs, when you see that mirrored finish on there, that is a sputtered coating and those coatings come from these things we call targets. What happens is, if say, you're doing a chromium target, at the end, if you try to molten cast it, if you had a bath or a melt of chromium, it would get oxides in it and be terrible. But, you can make very pure powders. That's one of the good things about HIPing is they can make very pure powders by blowing argon through a stream and it makes nice pure powder. Then, we can put it in and squeeze it into a solid billet and make a target which then can be evaporated in the vacuum chamber for coating.
We're seeing a lot of application now in ceramics. We see pump plungers and ceramic bearings. Here, at AIP, we do a lot of military work for armor, boron carbides, spinell (21:03), things that are really hard, ceramics. . . You want them perfect because if they have a defect in it, that's a starting point for a crack. A lot of brakes for jets and fighter jets.
We have a process inside the HIP that we call carbon-carbon impregnation. We take pressure and we push the carbon into the 3D woven graphite fibers and make brakes and nose cones. Other materials like beryllium, it's very hard to make beryllium and machine it because it's kind of dangerous, and so forth. Again, they take powders and the HIP the beryllium to make things like space mirrors and other jet parts.
Now, we've got into more things like teeth and braces are being done with ceramics- new transparent braces made out of aluminum and different materials, zirconia caps for your teeth. Again, if you don't HIP them and they've got a defect in it, it will be like a plate when you drop it. But, if you get rid of that defect, now you've got something harder than steel. On the other end we're doing jewelry such as gold and platinum rings. The benefit there is you don't have porosity. If you have porosity, it's like trying to sand a sponge and you can never find a nice perfect surface. But if you've got rid of that and the sponge is now hard, then you can polish it and you're not taking off any material.
It hasn't really happened too much, but we're seeing rumblings on phone cases. A lot of those have been metal in the past, but now they want to do the magnetic charging and it doesn't work real well.
DG: It's got to be glass of some sort, right?
CO: Yes. We're competing with Gorilla Glass. Some companies are looking at transferring that to zirconia. The iPhone watch, or iWatch, they were making it in zirconia, and that's one of the applications and things like that. Ceramic rings, ceramic knives, ceramic scissors – they're all being HIPed.
On the diffusion front, like the vacuum plates for the fusion reactor, like ITER, they can bond copper to tungsten and different things. You couldn't really weld them, because if you try to weld tungsten, it gets real brittle and cracks, but you can diffusion bond materials and you can do things you couldn't do otherwise.
DG: Those are great examples, and I think that gives folks enough. Are there any other examples that jump to your mind that you think people ought to know about, or is that it?
CO: The big one right now is 3-D printing. There is a lot of interest in 3-D body parts, titanium, stents, spines, implants for teeth and screws. Just about anything you can put in 3-D, they're trying to print. The problem with 3-D is, it's not perfect yet. Maybe in 10 years it will be perfect, but they're making imperfect parts when they print them. If you put them in the HIP and squeeze on it, not you've got a pretty much perfect dense part that's bonded better, stronger, improved properties.
It also allows you to print faster, so maybe you'll want to print an imperfect part, but you can just print twice as fast, so you increase the range between the particle and speed up your process. Again, price versus performance. You look at what the benefits of the two ways are.
DG: I've got a question. In heat treating, a lot of times after heating, you have to worry about dimensional change of the part, right? So, I'm thinking to myself, you've got a cast part with some innate porosity and you put it in a HIPing unit. Do you have to compensate, or do you have to be careful about dimensional change, most notably, I would think, with pressure shrinkage of the part?
CO: Very little because it's isostatic and we're talking about micro macro small porosity. If you had a 1 inch hole in the center and you were squeezing that out, you might give it up, but microscopic particle size is really not that much. Now, in the powder metallurgy, we say it's isostatic but then you do have some of the stresses in the container that you put around it. You might see some distortion at the corners where you welded a container, and so forth. But, there's good software out there, there's good programming and things and a lot of empirical data. People can pretty much design to shape within a couple millimeters.
DG: You mentioned this earlier, but the gas that's used is predominantly argon, because it's a heavy gas?
CO: The reason we use argon is the furnaces we use can't run in air or oxygen. We have a choice of nitrogen or argon, the two commercial grade gases. Nitrogen also embrittles materials like molybdenum. It tears up our furnaces, so argon is the preferred choice. Also, it has poor thermal conductivity which is good for the insulating portion of the HIP unit and when you get it dense enough then it does conduct good enough that it works for the part. It's the all around cleanest, best gas but it's an inexpensive gas. We do use nitrogen on some things. A lot of ceramics like silicon nitride we'll use nitrogen, for different reasons.
One of the biggest issues right now is we see a lot of interest in oxide ceramics. I've got many customers that want us to build a real high temperature oxygen furnace and we're real close to issuing that. What it will allow is to actually sinter in the HIP unit at high temperatures under partial oxygen which hasn't been done yet.
DG: Let's change gears just a little bit. You actually have two sister companies. I want to ask you two questions and you can incorporate information about those sister companies with this: One, why would a company want to outsource a HIPing process? And, two, on the flip side of that, why would a company want to purchase their own HIPing equipment and do it in-house? Maybe you can address both of those, because you've got experience on both sides, based on your sister companies.
CO: The outsourcing is really easy. If you've only got one part to HIP, you're not going to buy a HIPing unit. It's quantity versus can you support the operation of the HIP unit. And, you've got to do it profitably. You've got to do everything profitably or you're not going to do anything. You've got to look at the capital equipment cost and the space. Maybe you don't have space in your building or you don't want to build a new building, or, maybe you just don't have the people that have the knowledge in HIPing and you don't want to hire and train a maintenance crew, and so forth. Even some big companies like Pratt &Whitney and Wyam-Gordon both owned massive HIP units at one time and they decided it was cheaper to sell the HIP unit to Bodycote and then outsource it.
Sometimes economics may play in there, but sometimes maybe you want to have in-house sourcing. Maybe your part is so heavy, you can't afford to ship it. Then, you look at that and say you might want to have your own HIP for that reason, or you've got so many parts, you just can't afford to box them all, ship them out and bring them back. So, there are reasons why you'd want to own your own HIP unit.
DG: You've got sister companies that do the service, right? AIP, American Isostatic Presses, the company that you're with specifically, they build the units. But you've got sister company that actually does the service. Tell us about them a little bit.
CO: When we started out, we were just going to build HIP units and we were selling to a lot of the toll companies and we still do. But, around 2004, after the economic downturn of 2001, we decided we would get into building our own pressure vessels. We hired an engineer, Dan Taylor from Hydropack, and started building pressure vessels because we thought we could do it better. Then we were looking at toll. A lot of people would come to use and say they were not happy with turnaround or other things and they asked if we could help them toll HIP? We kind of got drug into it. We didn't, again, want to step on our customer's toes, so we came out with a different name and sort of hid behind that a little bit and didn't really even market it for a long time. But then again we kept getting dragged in, so we opened another plant and now, this last year, we opened another one. I've never seen a toll HIP company go out of business yet or lose money. Equipment building is up and down, you're riding the waves. It helped us flatten the curve a little bit. It flattened out the cash flow curve and it helped us a lot. Our competitors weren't doing it. They still aren't really doing it like we're doing it. The original name was Isostatic Pressing Services (IPS), then when we did our plant in Oregon, we called it ITS, Isostatic Toll Services. The family wanted to have different names and different people involved and there are different investors. It's AIP, basically, but there are other family members in the Persaud family. In Spain, the big one we opened last year, it kept the ITS name, but there are five players in that one, so we're one of the players.
DG: So, the sister companies have Toll Services, I know one in Oregon. And one in Ohio?
CO: The other is in Mississippi and then one in Spain. The Ohio one is under the AIP name. Basically, what we do in Ohio is we do more research. We, again, are expanding here in Columbus. We are getting ready to build again and we'll start heading a little more into the production toll. We've got a couple customers that are, again, pulling us that way. But, right now, Columbus has 5 HIP units, up to abut 500 mm in diameter. Most of it is high temperature. In Columbus, we concentrate on 2000 C. All of our other plants are doing production work which is medical implants and turbine type parts and those are all 1225 C roughly.
DG: Let's talk about some of the more latest advances, some of the newer things that are coming onto the scene. You mentioned one, I know, and that was the ceramic oxides. Let's talk about that a little bit more, and also, are there any other advances in the HIPing world that we should know about.
CO: I've been in it from almost day one, and it hasn't changed much. If you look at HIP from 40 years ago and today, they'd look the same. We still use the same valves and fittings. The big thing that has changed is computer control. AIP was one of the very first, I won't say the first because, again, back at Battelle in 1973, they had a Foxboro PDP that was in the whole room and had tape reels in it. I remember seeing it run a HIP unit, you'd type in STOP and START. It was like a movie.
Around '93 or '94, AIP branched into computer control pretty hard and we've kind of led since then. It allows us to do a lot of things, number one is that we can run it remotely. So, in Mississippi, we actually run our plant from Columbus. They load it and we take it over here. Our guys here in Columbus, they run our units all night by staying at home and watching them. Computers really help us there. As for service, we were able to get on the computer and look at a piece of gear in Singapore and fix it. That's the thing that really helped us.
"Where we're advancing things is in furnace technology for high temperatures, getting these furnaces to last longer, making them more reliable. . . We're trying to hit the everyday guy and make him profitable, get parts in and parts out."
Where we're advancing things is in furnace technology for high temperatures, getting these furnaces to last longer, making them more reliable. That's kind of one of the keys because, again, with costs and the economics of HIP is you want not to have to be repairing it and replacing things all the time. That's what we concentrate on. We don't try to push the edge. I think some of our competitors really try to push the edge and do things that may or may not be beneficial or even needed, but they're just trying to push the edge of things. We're not. We're trying to hit the everyday guy and make him profitable, get parts in and parts out.
As far as the oxygen, that's because ceramics has been coming for a long time and it's still coming. It's just never really taken off yet, but sooner or later it has to because they're higher temperature, stronger materials in steels, it's just we are competing against forgings and we re competing against casting companies. That's kind of the whole thing with all the HIP companies. There are basically only four main players in the world. We are all kind of small. We all kind of try to work together as much as we can and we all make good equipment to try to advance HIPing technology. More than beating up on each other, we try to beat up on the forging companies and the casting companies. We want to take their business.
In the research here, a lot of what we're doing is trying to work on the higher temperatures and higher pressures. If you can go to higher pressure, you can drop the temperature which then minimizes grain growth. In many materials, that improves either clarity of the material, if it's a transparent ceramic, or it can improve the strength of a steel because you have better interlocking between small particles. We're trying to do a lot more in high pressure, high temperature than some of the other companies. A lot of the companies are just in the metals only; they really focus on that. We're doing some really odd things here. We do stuff that nobody else wants to fool with.
DG: And you have fun while you do it! I'm curious, just from my own purposes. I envision these things as kind of like bell furnaces, a cylinder. Is that true? And, how big, on average, is a HIP unit? What's the work zone dimensions, let's say?
CO: They start with our smallest one which is about the size of a desk and it has a work zone of about 3 inches x 4 inches. We can build a little bit smaller, but economy-wise, we just built that one small model and that is the smallest that anyone uses. It's the size you need for a tensile bar. Just about every university and lab has an AIP small unit. Then, they can go up to massive units. The large one in Japan that Quintus built is 82 inch hot zone. That's a big diameter. They're talking about a 100 inch or 110 inch hot zone.
DG: That's diameter. How tall was it?
CO: 3 meters. Some people are looking at 4 meters or even longer. I've been told that the Army said if you can put a whole tank in one, they'd do it. One of the drivers there is turbine blades. As the blades get bigger, like on jet engines, your turbo fan is the outer blades and so forth, those big shrouds as they get bigger, the gas economy gets better, so they would like to build massive engines and they would like some of those parts HIPed. They want really big HIP units. Another one is in nuclear reactors for small modular nuclear power. They'd like to replace some forgings and if they could do it with powder metallurgy lids, and so forth, and those need a 3mm diameter HIP unit. The majority of the work is in the 1 meter range.
In a special Heat TreatRadio series, 40 Under 40 winners from the class of 2020 respond with their stories and insights of their life and work in the heat treat industry. This episode features the stories of Jamie Kuriger, Scott Cumming, and Shawn Orr.
Below, you can listen to the podcast by clicking on the audio play button and read a few excerpts from this episode.
"[I] Met a lot of different people, a lot of different industries where you typically wouldn't think that, on an everyday basis, that there'd be a need for heat treating, but that's kind of the cool thing about this industry."
"It [Covid-19] has made us have to diversify, look for new industries, look for new opportunities. . . We're seeing many many emerging markets, which I'm excited about."
"I'm blessed to be a part of this industry because it's, you know, it's able to be resilient. And the fact that there's still metal that needs to be heat treated, there's still so many opportunities."
"I was absolutely amazed at the range of products being treated. Maybe I was a bit naïve to how many products actually received some sort of thermal processing, from teeny screws all the way up to some giant crank shaft."
"As the younger generation, we must continue to question why things have been done a certain way. There's been many cases where I have been speaking with somebody about their current process, and ask how they've developed it. The response: that's the way it's always been done. In some cases, they don't even know why they're doing something a certain way. I love to find ways to improve and simplify processes and prove the old way is not always the best way."
"Prior to my involvement in the heat treating industry, I did not realize the material property benefits that heat can introduce for different materials."
"In recent years, things like digital communications, like ethernet IP, have been adopted by the industry giving better access to data from the furnace."
Heat Treat Radio host, Doug Glenn, interviews Greg Holland from eldec LLC on fluxless, inert atmosphere, induction brazing which could be a viable alternative to some flux-base furnace brazing applications.
Below, you can either listen to the podcast by clicking on the audio play button, or you can read an edited version of the transcript.
The following transcript has been edited for your reading enjoyment.
Doug Glenn (DG): We are here today with Greg Holland, a sales engineer at eldec LLC, in Auburn Hills, outside of Detroit, Michigan, and we’re going to talk today about a type of interesting induction technology. But first, tell us a little bit about you, your company, position, and how long you've been in the industry.
Greg Holland (GH): I'm a sales engineer at eldec. My main duties are inside sales, marketing activities, trade show coordinating, as well as being a coordinator and scheduler for our in-house coil shop.
Inert gas brazing: set-up Source: eldec LLC
I've been in the induction industry here for about five years now. Prior to that, I spent time in both air filtration and the thin films industry. I feel that my experiences there have really given me a wide background. It's made me a well-rounded engineer, in my humble opinion, but it's also given me a lot of perspective and some background knowledge that some of my colleagues here don't necessarily have, which has been a good thing.
eldec was established in Germany in 1982 by a gentleman named Wolfgang Schwenk. In 1998, he packed his family up and moved here to Michigan. He established what was at the time eldec Induction USA in 1998. His goal was to better cover the North American market, and what better way to cover a market like that than to be in the market? He continued to have eldec in Europe, and then he started it here in the US.
In 2001, we moved into the building we're in now, and we've been here ever since. We've grown the facility a couple of times; in 2013, eldec, as a whole, was purchased by the EMAG Group from the machine tool industry, which I'm sure a lot of your listeners are familiar with. At that time, we changed our name to eldec LLC.
DG: Greg, is there an area of specialty that eldec focuses on, or is it “all things induction”?
GH: I would say all things induction. Our office, in particular, does not do a lot of the heat treating. That is handled by our sister company here in the US, EMAG. This is mainly because if they're selling the machine tools, they are typically the customers that are then looking to heat treat. So, it makes more sense for just one person to knock on the door. I'm not saying that we aren't versed in heat treating, we definitely are. Prior to 2013, all of that was sold out of our office in North America, and we have process development capabilities that, I would say, rival what our sister company EMAG has. They are also in the Detroit area.
DG: We're going to talk about something you and I have spoken a bit about, and that is induction, fluxless, inert atmosphere. Let's start at the very basics and work our way through. What is this thing we're talking about?
GH: When you're brazing in normal air, you end up with oxides on your parts. If you don't get the oxides off of your parts, then they end up in the joint between the metal layers and the alloy. A lot of times, people will use a flux. What we are looking to do here is to eliminate the need for that flux; so, we would use an inert atmosphere.
"We are looking to try to get rid of that flux because it adds steps in your process, meaning you have to apply the flux. Then afterward, you have to clean the flux off of the part. A lot of customers aren't afraid to do that, but it's cycle time, right? You have an extra step."
DG: Basically, we're talking about brazing in an atmosphere, using induction without flux, and the primary reason is to get rid of those oxides. You kind of answered this already, but why do we need it? Why do we need that type? What's wrong with using flux?
GH: A typical braze process would use that fluxing agent, so it's either an extra paste that you would put on, or in the event that you have your brazing copper, you would have maybe a silver alloy that would have phosphorous in there. That phosphorous acts as the flux. As the alloy melts the phosphorous, it interacts with the copper oxides and basically cleans the joint for you. It also allows the alloy to wet flow and fill the joint gaps.
We are looking to try to get rid of that flux because it adds steps in your process, meaning you have to apply the flux. Then afterward, you have to clean the flux off of the part. A lot of customers aren't afraid to do that, but it's cycle time, right? You have an extra step. So, it's time, or maybe it's an extra person, whatever the case may be. By eliminating that flux, you've eliminated those steps. You don't have to worry about cleaning the part afterwards, and if you're washing the parts to get the flux off, then you don't have to figure out what to do with that wastewater.
DG: Walk us through a typical braze process that uses flux. Let me try this and you tell me if I'm good. Basically, you've got to apply the flux, and then you also have to apply some sort of a braze paste, I would assume, correct? The actual filler material?
GH: Yes. You can use a paste. What we typically use is solid alloy. If you're brazing, say in tube brazing where your joints are round, a lot of the alloy will come as a ring. You can get it specially made from a supplier as a ring, so it slides right down over your tube. If you have plates that you're brazing together, you can get a foil. It's essentially a thin sheet that you can put between the plates. You can also use a stick form, almost like a welding stick or welding rod type. Or, if you have a trough that you're trying to braze, you can get it in pellet form--little solid pieces that will go down into that trough.
DG: So, if you were doing it with flux, you would apply a flux first, then those things, and then, of course, you'd have all of the cleanup of the flux afterwards, I assume.
GH: Correct. And typically, even before you put the flux on, you want to clean the parts and make sure that you don't have dirt and dust and other types of debris in there, too.
DG: It sounds like this brazing process, where it's fluxless, is replacing a standard flux-based brazing. We've already answered the question about the significance of fluxless; basically, you're not having to use that. The other part of the description is that it's in an inert atmosphere. I would imagine that everybody knows what an inert atmosphere is, but if you don't mind, explain what is inert atmosphere and why we need it for this process.
GH: By definition, an inert gas is essentially a gas that doesn't react with anything. You're looking at helium, argon, or nitrogen. Technically, an inert atmosphere could also be a vacuum. What the goal is here, amongst some other things, is to get the oxygen out and away from the joint. By using a vacuum, you have to essentially create a chamber that is airtight. Because, as you pull a vacuum, if it's not airtight, the oxygen in the normal atmosphere is going to be seeping into that chamber.
The advantage of an inert gas atmosphere is, by filling the chamber with a nitrogen or an argon, you essentially create a higher pressure in the chamber than you do in normal atmosphere, and so you don't have to be airtight. In all actuality, you don't want to be airtight because you want to be able to purge that space and allow the air that is in there to flow out.
DG: So, you're back filling. And, by the way, for those listening, we will put a link on the transcript of this podcast, to the video that you sent that actually shows that process. It's hard to see on radio!
GH: That's actually a process that we have as part of our trade show display. At various trade shows we'll have different displays, and that one in particular, is stainless steel brazing in an inert atmosphere.
Inert gas brazing: at braze temperature Source: eldec LLC
DG: I'll describe it here just for a bit. Basically, there is a cylinder and they've got two parts inside that need to be brazed together. The cylinder, let's say it's a foot in diameter and maybe 16 or so inches tall, is a clear glass cylinder that comes down over the parts. I assume that you back fill with an argon or a nitrogen, and flush all of the oxygen out, and then it goes through a certain heating cycle and certain different KW and whatnot, and then cools at the end. Then, the lid lifts and you're off and running. That's basically how it looks
DG: Describe to us, if you don't mind, some of the industries that would use this process. What are the applications here?
GH: What we see is more so with stainless steel tube brazing, like fluid lines, automotive fuel lines, and that kind of a thing, where the end product doesn't get painted. It could be in an area that is visible to people, though, so they want it to look aesthetically pleasing. Those are the industries and processes where this gets used, but, ultimately, it can be used in any brazing application where you're currently using flux and don't want to have that additional step.
DG: You mentioned the automotive industry. Are there any other industries that you've seen it used in?
GH: We've had some other customers with essentially fittings on the end of a tube type of an application. I don't know what type of industries they ended up putting those into, but things like that are typically where we see these. But, again, it can be anything where you're heating, and honestly, it doesn't even have to be just brazing. If you have to heat something like that, you don't want to have the oxide layers and the discoloration. If you are back filling and purging that chamber with the inert gas, then as the part cools, and you allow it to cool in that inert atmosphere below the oxidation temperature, then you end up with a part that essentially doesn't even look like it was heated.
DG: Could this inert, fluxless, induction brazing potentially replace belt furnace brazing? Perhaps in some batch processes or torch brazing? Are there any savings in the process as far as manpower? I'm assuming you've still got to have somebody loading up the fixture to be brazed, right?
GH: Sure. You still have to have the fixture loaded. Depending on how the cell is laid out, it could be loaded manually, and it could be loaded by robot. You have some manpower requirements there. Typically, the actual loading isn't that much different than what you would have to do to load those parts into a fixture going through a belt furnace or to load them into a fixture heating them with a torch.
The advantage of induction over those two is not necessarily capital investment, but operating costs in the long run. You don't have the high cost of your gas. Typically, induction is more efficient than a furnace. It is a lot more efficient than a torch. You've got a guy out there with a torch that is heating your part, and then all of a sudden, he takes the torch and points it away as he does something else. All the while, the is gas burning, doing nothing. Again, with the furnace, whether you have a part flowing through there or not, you're heating that furnace and keeping it hot.
DG: Exactly. Whereas with induction, you're applying the heat and being done with it. Describe in a little bit more detail the actual process for an inert brazing process, fluxless.
GH: The chamber that you saw in the video is a large glass cylinder. They're not typically built like that. That one is built so that you can show it off and allow people to see what's actually going on. A lot of times, the chambers are much smaller. The goal is to make the space that you have to purge as small as possible, but still contain all areas of the part where the heat is going, because all of the space in that chamber has to be purged. That's an expense, so you want to limit that.
Now, depending on how long that purge cycle takes, how large your parts are, how long it takes to get to the temperature where oxidation starts to occur, you can start heating before the purge cycle is even done as long as you make sure that by the time you hit that oxidation temperature, all of the oxygen is gone. Then, you heat your part up to whatever temperature you need for your specific process.
Inert gas shield braze process where the customer wanted to eliminate oxidation in the joint area but was not concerned with oxidation of any other area of the part. As you can see in Figure A, the braze area and pipe coupling are inside of an inert gas shield and are not oxidized, whereas the housing is clearly oxidized (Figure B) as the braze cycle finishes. Source: eldec LLC
In brazing, it depends on what type of alloy is being used and what your base metals are. And then, depending on how the coil design had to be designed for your process in your part shape, you might have to allow some additional soak time. Say you are putting a really weird-shaped fitting on the end of a part; you might not be able to get a full surround coil over the tube that's going into that fitting and realistically get that back out of the assembly. You might have a coil that only goes around 120 or 180 degrees, so to allow the heat to transfer around to the rest of that joint and come to a uniform temperature for the alloy to flow, a lot of times you have a little bit of a soak time. Which is what you see in that video, as well. After the soak time, the operator can typically see through a little window; or with our power supplies, we create a recipe with a set temperature, set power, whatever the case may be if you're using a pyrometer or not, and a specified length of time, and through a little bit of process development in the very beginning, we can create that recipe. So, from a push of a button, the operator doesn't even have to see, necessarily, whether the alloy is flowing or not.
We know for development you need this much power at this much time, maybe you need two or three steps at different powers and different times, and then, all of a sudden, you know that you're going to have a good joint, you shut the power off and allow the part to cool again in that inert atmosphere. If you're not worried about aesthetics, maybe you have a part that's going to get painted and the oxides are going to affect the adhesion of that paint, or you know that you're going to have to bead blast the part anyway, maybe you're not worried about it cooling in the atmosphere, in which case you don't have that cooling step, you can just open the chamber (but be careful because then you just have a hot part). You could essentially just open the chamber and pull that part out.
DG: Would you have to do it all in an inert atmosphere, if that were the case? If you weren't worried about the oxides, you could almost do it without, at all, right?
"What we typically see there, is we're up against a furnace brace and it boils down to not only capital investment, but operating costs in the long run, what the part volumes are."
GH: If you're just heating the part. But if you're looking to braze the part, you still either have to use the flux or the inert atmosphere to keep the oxide out of the joint area.
DG: It went through the cooling process, so now it's done.
GH: Yes, that's basically the process. Then, your chamber would open once the parts cool and your operator or your robot could unload the part and load the next one. Because of the purge and cool down time, a lot of customers will end up with a unit, a power supply, that has multiple outputs on it.
For example, we’ve built a unit with three outputs for a customer multiple times. So, in that particular case, there’s a part that has two or three different braze joint locations on it. However, what you are essentially looking at is the operator. Even if it's the exact same part in all three cases, the operator can load the part in one location, allow it to start purging, and then he can load the part in the next location. When the purge cycle is over, you can have that heat time automatically start with a self-controller.
So, the operator is literally just loading station after station, and when the first one is done, the second one is loaded, purged, and ready to heat; then the third one, and off you go. By the time the operator comes back to the first one, the part is cool, the chamber opens, and he takes it out.
Essentially, you just have an operator that is loading and unloading parts and you've saved all that cycle time by having a machine that is incrementally more capital investment but saves you so much in cycle time and process flow.
DG: Right. So, you're using that cooling time or soak time to do another function which keeps your production up. Can you tell us, without naming companies, any specific examples of where this was implemented and specifically what processes it might have replaced?
GH: The one that had the three outputs that I just talked about was for automotive fuel lines. Again, I can't say the customer’s name, and I can't say which OEM the parts actually went into, but I can tell you that it was automotive fuel lines. What we typically see there, is we're up against a furnace brace and it boils down to not only capital investment, but operating costs in the long run, what the part volumes are. If it's a car model that they don't sell a lot, then they may not be able to justify the capital cost of the induction, but if you're running typical automotive volumes, then the induction portion, split over however many hundreds of thousands of parts a year, is peanuts in the end.
DG: Do you have a sense of what the cost savings was per part or anything of that sort on that example you gave?
GH: Unfortunately, I don't. A lot of our customers don't share that kind of information.
DG: Wouldn't it be nice if they told you, because it would be a great selling point to be able to say, “Hey listen, they were furnace brazing these that cost them so much per part, now they're inert fluxless brazing with induction and it cost X minus whatever per part.” That would be a great marketing thing.
DG: I guess it's probably worth mentioning here that eldec does all different types of induction, not just inert, atmosphere, fluxless brazing, right? You're doing all kinds of different types of stuff. We were just focusing in on that specific process.
If people want to get in touch with you, Greg, or just to check out eldec, where do they want to go?
GH: We can be reached through our website. eldec actually has two different websites. We have a website that is essentially a worldwide website. I think there's eight different languages on it that you can choose from. That is www.eldec.net. On that website you'll see a lot of product lines and applications.
But here, specifically in North America, we have developed a site called www.inductionheatingexperts.com. That site is more tailored to our market here in North America. On that site, you won't necessarily see as much of the heat treating, because as I mentioned earlier, our sister company EMAG handles that. If you're interested in that, their website is www.emag.com. Here in our office, our main phone number is 248-364-4750 and our general email address is info@eldec-usa.com. Me personally, you can reach me at my desk at 248-630-7756 and my email address is gholland@emag.com.
DG: I did have one other question and that is what other resources are offered by eldec?
eldec’s new online app, the Coil Design Assistant Source: www.inductionheatingexperts.com
GH: I mentioned our websites. Both websites will show a list of our products. There is at least one product line that is on the North America site that is not on the other site, and that's one that we developed and specifically developed here in North America. That's called our MiniMICO .
But also on our North American site is a tool that we've developed this year called the Coil Design Assistant. That's our CDA. I believe you guys did a little feature on it not that long ago, but that is a feature where customers can go on our website and essentially find a variety of different coil types and they can put in what dimensions they think they want or need and then we get an email and we can essentially do an approval drawing and a quote for them right there off of the web.
DG: Basically, it's a web tool to help you design a coil.
Doug Glenn, Heat Treat Todaypublisher and Heat Treat Radio host.
Heat TreatRadio host Doug Glenn and Mark Hemsath, talk about hardening basics. What is it, why does it matter, and how do we do it? This is a great primer episode to kick off our three-part series with Mark. Listen and learn!
Mark was formerly the vice president of Super IQ and Nitriding at SECO/WARWICK, and is now the vice president of Sales - Americas for Nitrex Heat Treating Services.
Below, you can either listen to the podcast by clicking on the audio play button, or you can read an edited transcript.
The following transcript has been edited for your reading enjoyment.
Doug Glenn (DG): Mark, I want to welcome you to Heat TreatRadio. Welcome!
Mark Hemsath (MH): Thank you, Doug. It's nice to be with you today and thanks for having me on the show to talk about this interesting subject. I'm not quite sure if I'm an expert on it, but we will certainly try to talk about it.
DG: I'm sure you know more than most of us – that's why you're here! First of all, as I mentioned, you are the VP of Super IQ, IQ being integral quench, not necessarily intelligence quotient – although, you are a smart guy. You are the VP of Super IQ and nitriding for SECO/VACUUM. Both of those are processes and both of those are dealing with hardening. Tell us a little bit of your background and then we'll jump into the topic of hardness of metals.
MH: I'm not a metallurgist. I did take metallurgy at college and I've been living it most of my life, but I didn't train to be a metallurgist. Instead, I got involved in the furnace business, and being involved with furnaces you have to do something with those furnaces. Typically, those furnaces allow you to do different things, like soften and harden metals. My background is that for many years, I worked with my father helping to design furnaces for the industry and we developed different furnaces. Some furnaces were for annealing, some for tempering, some vacuum processes, you name it. I joined SECO/WARWICK a number of years ago and I spent quite a bit of my early days in ion nitriding and SECO/WARWICK was involved with gas nitriding. That was of extreme interest to me. I took a liking to that and decided to become a subject expert on nitriding. Now, I've been asked to also get involved with our carburizing product, which is breaking into the market – we call it Super IQ. That is obviously carburizing as a surface hardening process. Not to mention, we also do through hardening in those furnaces, and we can go into some of those details a little bit more here today.
DG: For people who might not know, when we talk about hardness, we're talking about the hardness of a metal. Most people would think, all metal is hard. I mean, that's one of the characteristics of metal, but if you wouldn't mind, give us the “hardness 101” class: What is it and why is it important when you talk about hardness for metals?
MH: I think the most important thing is that with metals, you're trying to get certain features that allow it not to wear over time. At the same time, you want the part to last. You don't want it to break, you don't want it to chip, you don't want it to seize up, so there are a lot of different things you can do with the parts to give them certain wear characteristics and hardness. There are other things – anti-friction, etc. – that you can do with surface finishes, such as with nitriding, which offer hardness to the part, but in a slightly different way than you might think, just on basic hardenbility. But, whatever we're talking about, we're trying to prevent parts from wearing, and that's typically why you try to harden the parts.
DG: How do we measure hardness, or what are the units that we typically measure?
MH: You have different scales out there, depending upon what you're trying to measure. If you're just trying to measure the surface, you might go with the file hardness or you might go with a test where you don't have such a heavy hardness on there. There are different Brinell hardnesses: You've got the HRC, the HRB, and different scales out there. You've got the Vickers hardness, and all different types of equipment designed to very accurately measure the hardness of a part and also to try to figure out how that hardness is changing throughout the material.
Typically, in most materials and in the processes that you're doing, because you have some thickness of material and a lot of it is related to both the quench rates etc., you're going to get hardness that varies throughout the part. So, they have come up with different ways of measuring that and there are a number of different scales out there. You can look that up and decide. Some people like to use one over the other, but typically, they are all designed to do the same thing: try to get an accurate reading of what the hardness is.
DG: I've heard the more common ones, I think you've mentioned them: Rockwell is a hardness measurement, Vickers is a hardness measurement, and Brinell is a hardness measurement. So, those are the scales that are used. We're not going to get into how those tests are done and things of that sort, but we certainly could at some point in time.
[blocktext align="right"]“I think the most important thing is that with metals, you're trying to get certain features that allow it not to wear over time. At the same time, you want the part to last.”[/blocktext]
MH: I'm not an expert on doing the tests. I've seen them done many times, but there are guys that are really good at that. Same with microstructures, right? Looking at that and understanding how things change within the steel and seeing it under different magnification, gives the scientists some really good knowledge about what's going on within the steel.
DG: Again, “hardness 101”: A person often hears, when dealing with metals and hardness, about surface hardness or through hardness. Can you tell us about those things? What's the difference? Why is that important?
MH: A part that you make, in a lot of instances, you want it to be as hard as possible for wear characteristics, but at the same time you don't want the part to fail because the core properties are too hard and can be brittle. Typically, what you have is people trying to impart certain types of features onto the surface and still retain the so-called core properties of that material. Obviously, you heat it up to austenitic temperatures and you quench it and you try to transform as much of that steel as possible to martensite, and then you try to temper it back.
A number of things that you're doing there are going to change the properties of the steel. That's why people will use different tempering temperatures to get different core properties. They'll use different surface treatments, whether carburizing (which will give you a higher surface hardness by driving more carbon into the surface) or induction hardening, in which you're heating up just the outer part of the steel and then quenching the outer part. Obviously, you can only go so deep because you're quenching it from the outside, but that will give you almost a double type of feature within the material. You're starting out with the core properties that you want – a certain hardness, a certain ductility, and a certain capability to function, let's say, a shaft – and then you want to give it some hardness. If you have the right steel, you can harden that just by taking it up to temperature with induction heating or with flame heating and then quickly quenching it to get the properties that you want on that outer.
DG: There are some properties in there that I want to make sure our listeners understand. You mentioned the idea of hardness and ductility. Those two things tend to be on opposite ends. I know there are much more technical descriptions of this, but the harder something is, the more brittle it tends to be, and when it's brittle, it takes less to crack it or break it. Whereas if it's ductile, it's softer, it can take more of an impact without breaking. For example, let's just use a gear: On the gear teeth, on the outer edge of the gear, you want that to be very hard so there's good wear, but you don't want it to crack so you keep the inside of that gear, (that's away from the surface side of the gear), soft. Yes?
MH: Yes. And there is a lot that goes into gear design. You don't want high impacts, obviously, you want the teeth to mesh together. There are people that induction harden gear teeth, there are people that carburize gear teeth and there are people that nitride gear teeth. They're all trying to do something on the teeth, and even though you're doing something on the teeth, you still have to also impart certain properties to the core part of the gear itself to make sure that nothing breaks or falls apart on the gear, the main core part of the gear itself.
(Source: Inductotherm)
DG: You did also mention the fact that there are some steels that are more easily hardenable than other steels. I've heard there are high hardenability steels and there are low hardenability steels. What's the difference?
MH: In general, iron is an element that is common to all steels. Now, there is tremendous science that has happened over the last decades on putting different alloying elements into the steels, whether it's chromium or titanium or vanadium or you can name all the different ones. Some of them are called micro alloy and some of them are more main alloys, but they all provide different types of properties to that alloy steel which then gives that steel certain characteristics. There are more steels created today than I could ever mention. You can buy huge books on that from ASM and get all of the different properties of the steels. Tool steels have quite a few alloying elements in them, and they have a very high hardenability. They're also more expensive, so people are not going to want to use expensive steels with all of those expensive alloying elements for basic automotive transmissions, or what have you; it just gets too expensive.
I should also say that carbon makes up a big part of that, too. The carbon in the steel is, obviously, why we call it carburizing because it will put hardness into it. But we also have what we call low carbon steels, medium carbon steels and high carbon steels. Then you start throwing in the alloying elements with that and you get all kinds of variations.
DG: So, typically, a high carbon steel is going to be much more easily hardened because it's got more carbon in it to start with and you don't necessarily have to add carbon into it during the heat treating process.
MH: Right. But when you heat and quench those parts, they also have different properties, as well.
DG: Is it only steels that can be hardened?
MH: I'm not an expert on it, but there are other types. There are some stainless steels – martensitic stainless steels – and there are different age hardening steels… which are still steels. There is aluminum, which has different properties depending upon what other elements they put in that; they can do some different types of hardening on those. Titanium by itself is a fairly hard metal, etc. Most of the people that we deal with, or whom we're talking about, are the people who are using steels to start with, a lot of times fairly inexpensive steels. But, we also, in vacuum furnaces, do very high-end steels, such as tool steels, like H13 air hardenable tool steels, etc.
DG: Let's jump back to steels. What are the typical heat treatment processes that enhance hardness, that increase the hardness?
Microstructure of the carburized steel. Source: Surface Hardening Vs. Surface Embrittlement in Carburizing of Porous Steels - Scientific Figure on ResearchGate. Available from: https://www.researchgate.net/figure/Microstructure-of-the-carburized-steel_fig2_326653574 [accessed 3 Mar, 2021]MH: First of all, we have carburizing. As we spoke before, when you have a steel and you impart carbon into that steel, it tends to make it harder. What carburizing does, is it focuses that effort of putting carbon only into the surface. This means that you can have different core properties of that steel versus the outer properties. Then you can drive that carbon fairly deep into the surface, if you want. Now, deep means something like 2 mm, and above that are starting to get fairly deep cases. 2 millimeters is .079 inches. You do this by putting the part, at austenizing temperatures, into an atmosphere which is rich in carbon.DG: Let's stop here to define. Again, this is a non-technical definition of austenizing. To me, when I think of an austenizing temperature, that means even though that part is still “solid”, the fact of the matter is, that piece of metal is kind of in solution; things are moving around inside.MH: You've changed the structure. Then, when you quench it, you're trying to cool it very quickly so that you can get different structures out of that steel.We're talking here surface hardening or surface engineering. There are quite a few, actually. Some of the more common, obviously, are the ones we talked about here. There are basically four very common ones: carburizing, nitriding, carbonitriding, and nitrocarburizing. They are different. (Although, in Europe, sometimes they reverse those names a little bit between carbonitriding and nitrocarburizing.) I'll explain to you what, I believe, those are and why we call them that.
Carburizing is just as I was saying: driving carbon into the surface of the steel. It gets a very high hardness in the steel, depending upon what type of steel you have. It's typically done with lower carbon steels so that you can put the carbon into the surface. That's why we do it, because it's a lower carbon steel.
Nitriding is not an austenitic process; it is a lower temperature process. It's called a ferritic process. What that means is you don't go into the phase transformation where you have to go and quench the steel to get those properties. You're not going to get much in the way of dimensional shift or growth that you would get from the austenizing steel, and that's very beneficial. By driving nitrogen into the surface, you get a very high hardness. Now, you also need to have things in that surface of the steel other than just iron. You have different alloying elements which combine very easily with nitrogen, such as chromium, titanium, aluminum, vanadium, and some of those other things which will combine with the nitrogen, which either comes from an excited nitrogen atom via ion nitriding or comes from the disassociation of ammonia from gas nitriding where the nitrogen then transports itself into the steel surface and making those hard items.
[blocktext align="left"] “Nitriding is not an austenitic process; it is a lower temperature process. It's called a ferritic process. What that means is you don't go into the phase transformation where you have to go and quench the steel to get those properties.”[/blocktext]
In carbonitriding, it's identical to carburizing except you throw some ammonia in there. This is typically done at a lower temperature because ammonia breaks down very quickly at high temperature, so you're trying to stay right at the lower edge of that. You're throwing ammonia in there because the nitrogen will impart a very hard surface along with the carbon. It doesn't go in as deep but it's usually done as a 'down and dirty' very hard surface on a part, typically, a fairly inexpensive part.
Nitrocarburizing is like nitriding, but the focus is on the white layer, on the compound zone, which is a very hard layer of iron nitrides and iron nitrogen carbides. You get a very hard layer. They call it the compound zone because you have both a gamma prime zone, which is one element, and you have an epsilon zone, and those have very unique properties for the surface of the steel.
DG: Those are the main carburizing processes – carburizing, nitriding, carbonitriding, and nitrocarburizing. We'll dig deeper into those in our next episode, and also cover the processes, perhaps the types of equipment that those processes are done in, just for a little bit more education. Then, we’ll do a third episode where we'll talk about why we're hearing more recently about nitriding, low pressure carburizing, and single piece flow – and perhaps something that is near and dear to your heart, Mark, and that is some hybrid systems of a batch interval quench, which your company happens to call the Super IQ. Thanks for being here today.
Doug Glenn, Heat Treat Today publisher and Heat Treat Radio host.
To find other Heat Treat Radio episodes, go to www.heattreattoday.com/radio and look in the list of Heat Treat Radio episodes listed.
Heat Treat Radio host, Doug Glenn, conducts Part 3 of this 4-part series with James Hawthorne of Acument Global Technologies and Justin Rydzewski of Controls Service, Inc. about Revision 4 of CQI-9. We will hear about changes in process tables and key information on how to read this revision of CQI-9.
The following transcript has been edited for your reading enjoyment.
Doug Glenn: Welcome everybody. In the first episode of CQI-9 Revision 4, we covered pyrometry and Justin mainly covered it because he’s the expert in this area. In the second episode, we spoke primarily with James and he shared about changes in the heat treat system assessments (HTSAs) and job audits areas. Justin, if you don’t mind, would you please review with us just exactly what CQI-9 is?
Justin Rydzewski: It has essentially three primary sections. You have your heat treat system assessment, which is often abbreviated as the HTSA; you have the pyrometry section; and then you have the process tables. The job audit is also something that needs to be completed on an annual basis, so it’s a minor section to the document.
DG: Today we’re going to talk about process tables and some other support portions of the spec. Let’s jump in. James, if you don’t mind, maybe you can talk to us a bit about what are these process tables and why are they important?
James Hawthorne: The HTSA covers the heat treat system and assessing that system. There are very unique processes that are covered by CQI-9. Those are captured in the process table section of the CQI-9 document.
Process Table A covers carburizing, carburnitriding, carburrestoration, austempering, and precipitation hardening or aging. You’ve got sections like B- this covers nitriding and ferritic nitrocarburizing. Then you have process table C which covers aluminum. Process Table D covers induction. Process Table E covers things like annealing, normalizing the stress relief. And we go all the way up to process Table I. So, there is a process table for each unique type of heat treat that is out there in the industry and this allows some very specific topics to be covered in those types of processes. They all cover pretty much the same thing, so I’ll go back just to run through the headers of Process Table A.
The first portion of it is Process and Test Equipment Requirements. What are the rules of engagement for those items? The same thing for pyrometry. There are specific call outs in the process tables. If this is part of your system, you have to play by these rules. Some of them will point you to specific sections of pyrometry. So, if you’re looking at the thermocouple and calibration of thermocouples, the process table is going to tell you that you shall conform to section P3.1 which covers all of those.
Interview with Justin Rydzewski, James Hawthorne, and Doug Glenn Source: Heat Treat Radio
It also covers the process monitoring frequency. How often do you have to check your temperatures? What are the rules of engagement? It calls out specifically each portion that may be included in that type of process. If you have a batch style furnace that covers that process, it has certain rules for you to manage your batch process. If it’s a continuous furnace, you have certain rules on how you would manage that continuous. If your process has an endothermic or exothermic generator or even some type of nitrogen methanol system, there are rules of engagement on how to manage or review that system for those items.
Then you get into things like inspection. Your in-process and final test parameters are also covered here. The last portion of it, in section 5 of the process table, is when you get into things like your quenchant and solution test parameters, and what are the rules for checking that.
What’s really nice about the document is that as you traverse the document, for instance, we have in the quenchant and solution test parameters, it’s A5.1. The next column over, it tells you what is the related HTSA question. It is set up in a way where you can go to the HTSA right from the process table and see if you’re compliant to what’s listed there as the shell statement and the requirements or the frequency for checking those.
DG: That answers another question we were going to address, and that is, how do those process tables work with the HTSA? It sounds like, in a sense, they are cross-indexed. Is that it?
JH: That’s correct, Doug. Like we spoke about in the last interview when we were talking about the job audit, the job audit is set up the same way: It has that same column, it tells you what the related question is, and it affords you the ability to easily traverse the document from the questions in the HTSA to the requirements in the process tables.
DG: Justin, anything else from you on that?
JR: The way that I typically frame it for people new to CQI-9 is that the process tables essentially define two things. First, your tolerances for process and test parameters, and second, your frequencies for those process test parameters in testing parts, which are specific to each heat treat process.
As James mentioned, there are nine process tables. The requirements in each of those process tables are going to be specific to that process. The requirements within the HTSA are intended to be broad and generic. They’re intended to be applicable to any organization performing one of those heat treat processes. As you go an HTSA, you will be notified when to refer to the process table for some specific aspect of the tolerance or frequency portion on that particular requirement.
DG: It sounds like a lot of work has been put into the cross referencing, making it simple and making it user friendly, right? So, whether you’re in the process or whether you’re in the HTSA, you can quickly and easily find the portion in the other section of the spec that applies to what you’re doing.
JH: That’s correct. Plus, it does afford you the opportunity to find compliance in a simpler fashion.
JR: And to also specify tolerances and frequencies that are appropriate for that given process. If I’m heat treating aluminum, I might have a tighter tolerance than that of hardening steel. They are very two different processes susceptible to different things, so the values need to be different.
DG: When you’re looking at the changes that were made from Rev 3 to Rev 4 with these process tables, is there anything that jumps out at you?
JR: I think one of the most notable changes is an item that wasn’t changed, actually, and that was the formatting and grading system retained from the 3rd edition. The primary focus of our efforts with the process tables this go-around was to enhance that clarity. The most notable change across many of the process tables was the added requirement to continuously monitor and record that temperature control signature for generators. So, for atmosphere generators, that temperature side of things needs to not just be monitored, but also recorded.
DG: Having taken just what we’ve heard today about the process tables, thinking back to what we covered in the last section on the HTSAs, and going back, Justin, even to your first episode that we did on pyrometry, it seems like there is a lot of stuff here. The CQI-9 comes in at 115 pages long, I’m guessing there are going to be people that start dipping their big toe into this thing and say, “What the heck? I’m struggling here! I don’t understand. What’s required of me?” From what we’ve talked about, before we hit the record button, there are some other very helpful things in this spec besides these table requirements and things of that sort.
Let’s talk about those a little bit. What are some of those other resources that will help simplify the execution of this spec?
JR: There’s a lot to it, but the underlying intent was not to confuse or bombard the organization with unnecessary rules and just allowing people to figure it out on their own. Everything goes through a “stink test” as we’re writing this up. Everything must make sense to us. If it doesn’t, it’s typically not added in or it’s refined and beat up until it is okay and then added in.
What can we do or what are the things that would be helpful to the end-user to make sure that they’re adhering to these things and that they understand to a point where they can adhere to it? It is not uncommon for me to find my customers having no problem following the rules so long as they know what they are so that can understand them and they make sense.
To convey that and get that buy-in, we’ve added a few elements and refined others. I think the most significant one, and it is in the section within the document that I reference most, is the Glossary of Terms. There is a lot of really good information in there. It’s not that I’m referencing the Glossary of Terms because I don’t understand what the word “calibration” means or what the difference is between a “control thermocouple” and a “monitoring thermocouple”, it’s how did we define those terms relative to CQI-9 in terms of CQI-9? How did we intend that word to be utilized? Sometimes you can find those little bits of detail that make it easier to understand or to capture what some of the requirements are for that are noted within the rest of the main document.
JH: There are also some illustrations added to the Glossary as well. There were a couple there before, but there was some refinement to those illustrations that were in there. Even those harder to define portions where we put those illustrations to help drive home the intent of the message, I think that was done very well in the Glossary section.
DG: Would you say, James, that that’s the major change to the Glossary, or are there other things that changed there?
Source: Markus Spiske st pixabay.com
JH: We went through the entire document from cover to cover. There are many, many minor changes across the board, but there were some definitions that were added to the Glossary as questions came up during our normal meeting cycles, or that came from end-users when asking them how we should define something.
As those questions came in, we added those definitions to help with that guidance. Especially, as Justin said, as we’re talking in the meetings, if we’re hammering away at it and we have it digested in the room – we understand what we mean – how do we send this message to the rest of the users out there in the world? The Glossary ended up being a great place for items like that, as well.
JR: Right. So instead of using six paragraphs to describe a certain requirement or whatnot, just use proper terminology and then let’s define adequately those terms, which may be contested or not fully understood immediately, in the Glossary of terms so that there is a clear idea of what it is we’re trying to get across and not have to make this thing 185 pages.
[blocktext align=”right”]“In the context of this document [the CQI-9 revision 4], the following definitions shall apply.”[/blocktext]A real good example of things added into the Glossary would be terms that perhaps we all take for granted, terms that you understand what it means, but when you poll ten different people, their definitions are just slightly different. For example, “grace periods” was a word we added into the Glossary. Not that it’s an overly complicated term to understand, but relative to the document, it can have an impact on how it is you interpret those certain requirements and what it is that it means for you. “RTD” was another one added in there from a sensor standpoint. I think another that might get some attention is the inclusion of “sintering” and “sinter-hardening.” There was a fair amount of contention on the sintering side of things that CQI-9 wouldn’t apply. Then we included sinter-hardening, but we didn’t necessarily define the difference between the two processes. Now, there’s a distinction made, and it’s included in the Glossary.
DG: As far as the Glossary goes then, is there any guidance on when it should be used?
JR: Personally, I would say as often as possible. It is an incredibly overlooked portion of this document. It is amazing how much confusion can result just from misunderstanding a word that was used. Using the example of “grace period”; it’s not that I don’t understand what grace period means, it’s that I want to know what grace period means specific to CQI-9. How is it intended to be utilized? My definition might be different. I want to make sure that I’m lining myself with the definition of the word as it’s defined.
There is a statement at the beginning of the Glossary that says, “In the context of this document, the following definitions shall apply.” So, it’s within the context of this document. I may have a different context of that word, but it doesn’t matter what my definition is, it only matters as to how it’s defined within this book, the context of this document.
DG: That’s a good encouragement to have people refer to that Glossary. Even if you think you know what the word means, it’s probably not a bad idea to make sure that you understand how it’s being used in this document and don’t impose your own definition.
JH: There is one other thing I would offer, as well. I totally agree with what Justin is saying, and I think this speaks volumes or reinforces the things that we’ve talked about already on how one portion of the document supports the other portion of the document and supports the other side. This document, through and through, supports itself.
[blockquote author=”James Hawthorne, Acument Global Technologies” style=”1″]This document, through and through, supports itself.[/blockquote]
DG: Let’s jump to instructions. Probably the most important part of any spec or document is the instructions. Let’s talk about those for a moment, including maybe references, illustrations, figures, and things of that sort. Major changes? What should we know about instructions, references, illustrations and figures?
JR: There are support elements within the document that we’ve spoken about with the glossary of terms and what not, but there are also instances where instructions are called up… Step-by-step instructions on how to do something so that you can feel confident that you’re doing it correctly. For doing the HTSA (heat treat system assessment), there are instructions for completing that with the process for going about doing the assessment there, or even as simple as completing the cover sheet for the document or the job audit. There are instructions provided throughout to try to encourage and support someone’s effort in adhering to the requirements in the document.
DG: Let’s talk about references, illustrations and figures.
JR: Within the pyrometry section, specifically, there are a lot of instances of illustrations. For the system accuracy testing illustrations, the intent is instructional. It is to allow someone a means of seeing it visually both how it’s to be performed and how to correctly perform it.
Whether it’s a probe method A system accuracy test versus a probe method B system accuracy test, the illustrations included now are a bit more clearly refined. The focus was on eliminating anything that was unnecessary from that illustration to allow the user to more easily focus on those elements that are critical. The user will find a lot of improved illustrations throughout the pyrometry section.
You might have no issues performing a system accuracy test and you might have been performing them for some period of time. However, it’s still a pretty good idea to make sure that you’re doing it in the manner that CQI-9 requires in order to see if there is anything in there for added guidance and to make sure that you’re not overlooking something. That just includes simple math to perform one of those tests. Those are also illustrated to show progression of how to go about doing that test properly.
DG: Are there other resources within this spec that are available to help the user?
JR: If there is still confusion, it’s not hopeless. There are other means by which people can reach out to try to get clarification on different interpretations of requirements. James and I just recently participated in a roll-out where we had a Q&A for people to bring their questions regarding confusion around certain requirements. We provided answers from a clarity standpoint. That support doesn’t go away, nor is it just available at special events like the roll-out. At any time, people can, and often do, email into the AIAG with their questions, looking for guidance on certain matters.
If it’s as simple as- “I don’t understand question 214,” write in and ask the question and see if you can get some additional guidance. If it’s “I don’t understand pyrometry,” that’s a bit of a broader question and you’re probably not going to like the answer you get back (~chuckle~) and you’re probably not going to get what you’re looking for in the answer you get back, but there are many other sources for support outside of the document.
Justin and James recommend reading the whole document and participating in question submission forms to gain a greater understanding and voice in the CQI-9 requirements.
If the document doesn’t have enough, look outside the document. The AIAG is one of those sources. Your customer is another one. If you work with outside service providers (I’m speaking from my world of things – pyrometry), lean on them for guidance and things you don’t understand. I have my nose in these documents constantly, so my understanding of it is pretty alright. I can afford some additional guidance or interpretation.
I guess the advice I would have is don’t jump at something blindly and say “it’s going to be enough.” You’re going to want to have something behind you to give you a little bit more substance than that and to have some confidence in what you’re doing. Otherwise, it will have the tendency to snowball on you.
DG: Because these documents are “living documents”, they are continually evolving. Let’s say someone has a suggestion for a change that they would like to see made in a future Rev 5, what should they do?
JH: At the back of the book, we have what’s called a maintenance request form. The maintenance request form is a very short and sweet form that allows document users to submit for committee review what changes they believe should be made. This would give them the forum to always have their voice heard and how they feel, or believe, something should be managed.
To go back to what we were talking about, the CQI-9 technical committee still meets quarterly. As Justin alluded to, we had questions from the roll-out, but a good portion of our first post completion meeting was answering questions for the heat treater at large to help give that clarification. And, when we come across a question where we don’t really know what the person is asking or looking for, we give those questions back to our AIAG representative. They may reach out to that submitter to gain clarity on what was being asked so that we can give the best answer possible, not just potentially dilute it by giving an answer just of the sake of answering the question.
There is a lot of opportunity there and as these maintenance request forms come in, they will be handled. They’ll be handled with the committee and the group will work on it and develop the best answer. That answer may be, let’s look at making a change, whether that’s through some form of errata or by “putting it on the shelf” until – hopefully a long time from now – we look at a 5th edition. This gives us the ability to capture these things and make sure that it stays on out radar. We want to make sure that they’re taken care of with the urgency that’s needed.
JR: I think an item of note here, to make it clear, is any of those maintenance request forms that are sent in, all of them are reviewed by the technical committee. They are all reviewed. Anything submitted will make its way in front of that committee to be reviewed to on their agenda.
DG: What should these forms be? Is it just for document changes or for other things as well, for suggestions and whatnot?
JR: It’s for document changes as well as a suggestion box form.
DG: We’ve covered a lot in this third episode. We’re going to have a fourth episode that is going to deal with some practical tips from you guys on the actual execution of these things, but is there anything else that you would want to tell the listeners regarding the spec itself? Any other concluding comments?
JR: From a process table standpoint, this was something that was reiterated throughout the entire roll-out presentation: it really does take reading the entire document to capture all of the changes.
Some of them are quite minor and some of them stand out as being significant, but for the most part, they are minor, and sometimes minor ones can be very easy to overlook. There used to be requirements for calibrating your hardness testers on an annual basis. Those requirements have now been expanded to all lab and test equipment that require an annual calibration.
Another element that was included in the 4th edition was we made an effort to increase the clarity and guidance for the use of exceptions that are applicable to section 4 requirements of the process tables. For example, these would be used if you’re employing a surrogate test piece in lieu of sectioning some large or expensive product. If anyone is interested, the clarity is included on page 9.
But make note, these are not blanket requirements; these exceptions require customer approval and ultimately OEM approval, so they must be documented and approved by a customer and increased in your PPAP (Production Part Approval Process) control plan. There is a fair amount of added clarity on that topic, so it’s something people might want to take a look at and dive into just to make sure that they’re familiar with it.
DG: James, any concluding comments from your side?
JH: I think I’d just reinforce a little bit of what Justin was mentioning earlier. Read the document. Read as much of it as you can and try to understand as much as you possibly can. We made a lot of changes. Some of them are very minor, but some of those minor things could potentially be overlooked if you don’t step back and take a moment to understand the document and how each system, or each portion of the document, works with each other.
DG: The next episode is going to have some practical tips. We’re going to pick the brains of these two gentlemen on navigating Revision 4. You won’t want to miss it. There are going to be opportunities here to basically figure out some of the details.
If you have questions, feel free to send them in. You can email htt@heattreattoday.com if you have any questions and we may get those answered.
Doug Glenn,Heat Treat Today publisher and Heat Treat Radio host.
Heat Treat Today publisher Doug Glenn and Marc Glasser of Rolled Alloys on why choosing the cheapest material is not always the best way to go. Listen to some of the practical tips Mr. Glasser gives for choosing the right alloy for your application.
How well do you know hardness processing? Can you draw the line where nitriding and ferritic nitrocarburizing (FNC) differ? In this Technical Tuesday feature, skim this straight forward data that has been assembled from information provided by four heat treat experts: Jason Orosz and Mark Hemsath at Nitrex, Thomas Wingens at WINGENS LLC – International Industry Consultancy, and Dan Herring, The Heat Treat Doctor at The HERRING GROUP, Inc.
