Cemented carbide is often used interchangeably with other terms in the industry to describe a popular material for tool production. However, the specifics of what makes up a cemented carbide, and how this material can be processed, are not so widely discussed.
In this best of the web article, discover the composition, applications, and processes involved in sintering cemented carbide, as well as how vacuum furnaces play an essential role for this material. You will encounter helpful diagrams and resourceful images depicting each step of the process.
An Excerpt:
“Hard metal, or cemented carbide, refers to a class of materials consisting in carbide particles dispersed inside a metal matrix. In most cases, the carbide of choice is tungsten carbide but others carbide forming element can be added, such as tantalum (in the form of TaC) or titanium (in the form of TiC). The metal matrix, often referred as ‘binder’ (not to be confused with wax and polymers typically used in powder metallurgy) is usually cobalt, but nickel and chromium are also used. This matrix is acting as a ‘cement,’ keeping together the carbide particles (hence the ‘cemented carbide’ definition).”
All the buzz in our industry seems to indicate that additive manufacturing (AM) and 3D printing are the next hot topics in heat treat, particularly in vacuum heat treat. Heat Treat Today decided to find out how these new technologies are shaping the industry. Read what five heat treat industry leaders had to say about how their companies are preparing for the next generation of AM and 3D printing.
This Technical Tuesday article bringing together the responses from these five companies was first published in Heat Treat Today‘s November 2022 Vacuum print edition.
What changes have you made to accommodate the AM/3D printing marketplace?
Dennis Beauchesne General Manager ECM USA, Inc.
The most important changes relate to the build plate size and how it connects to our standard size systems. Build plates are ever-changing, it seems, as customers have new applications and mostly larger build plates are being requested. In addition, the process parameters – such as temperature and time at temperature and quantity of material – are important. These two items have the most to do with reconfiguring equipment for the AM market. We have also been able to implement our wide range of automation and robotics skills into this equipment as the market scales up for high production.
How will your products and/or services change to accommodate this marketplace?
We are/will be introducing equipment that is in line with standard-build plate dimensions along with reducing operating costs.
Share how 3D printing or AM products/services help heat treaters.
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Recent debind and sinter applications have involved, as previously mentioned, complete robotics to handle parts after printing, to debind, to sinter, and then to process specialized by ECM, such as low-pressure carburizing. ECM has also provided equipment to provide all three processes in the same furnace without moving the load or requiring the furnace to cool and reheat. This reduces work processing time along with less handling and less utility cost.
What changes have you made to accommodate the AM/3D printing marketplace?
Mark Hemsath Vice President of Sales, Americas Nitrex Heat Treating Services
Nitrex Vacuum Furnaces, through its GM Enterprises acquisition, has moved heavily into additive manufacturing via large production MIM furnaces, which are able to both remove large amounts of powder binders and sinter the parts in the same process. We are in the process of installing and/or starting up five furnaces for these markets, and we have recently employed even more advanced concepts on high volume wax removal. A further trend is on higher value materials, like nickel and cobalt alloys and titanium, necessitating diffusion vacuum levels for processing. Nitrex Vacuum has had this experience already for many years, so moving to smaller scale 3D designs comes with years of experience.
How might your products and/or services change to accommodate this marketplace?
Smaller units are a trend to keep an eye on. We have over a decade of learning from the large units we offer, and this will allow us to compete in these lower volume markets (i.e., 3D) via our proven expertise. Several facts/ideas that we are keeping top of mind are:
Large potential in the future (whole new market starting to evolve)
Redesign the product to meet the new needs
Good for rapid prototyping and quick low volume parts
Furnaces need to be available with fast delivery 3D printing is finding a tremendous niche in fast part production, sourced internally or sourced quickly. These parts may cost more per piece, but having them fast is often more important, and 3D offers this ability to cut weeks or months off of supply chain sourcing.
Share how 3D printing or AM products/services help heat treaters.
The AM sector is still in growth mode. How we help is to give a full-service solution to those customers who want to really increase their volume yet use vacuum in the process. Vacuum helps to transport the binder vapors away from the parts and into the traps for removal. Full binder removal adds to the quality of the parts, as does vacuum sintering of the final parts. We have supplied a few systems over the years with higher, diffusion vacuum levels. As powder materials evolve to higher value materials, there is more interest in diffusion vacuum, and we recently supplied such a system.
What do readers need to know about AM/3D to make decisions today?
Vacuum is the proper way to debind and sinter. Additionally, 3D printing started slow and there were many technologies evolving. Now, it has started to really grow, and the need for smaller furnaces that can offer the same quality as MIM parts produced in high volumes will be a need for 3D part makers, in medium to low volume parts. This may involve furnaces for sinter only, debind and sinter, or even sinter and heat treat. We can see the need to both sinter 3D parts in a small furnace and also heat treat them with special added processes and surface treatments.
What changes have you made to accommodate the AM/3D printing marketplace?
Phil Harris Marketing Manager Paulo
Adding a hot isostatic press has been the most notable change Paulo has made to serve the growing AM market. It goes a step further than that though; heat treatment of AM parts has rapidly evolved, and the desire for custom cycles and more data has caused us to make instrumentation changes and do more R&D type work. Understanding the full production path of the parts and doing our part to reduce the time parts are spending in post-processing steps, including offering stress relief, HIP, EDM, and vacuum heat treatment in a one-stop-shop.
How might your products and/or services change to accommodate this marketplace?
As trials continue and boundaries are pushed for both additive and the accompanying thermal processing, we’re constantly keeping an eye on what’s next. Investing in equipment that’s capable while maintaining and instrumenting it to provide the data and reliability the market needs is the name of the game. Of course, open communication with additive manufacturers and printer designers makes this far easier. We value communication with printer manufacturers as it helps us understand demand for our services in terms of build plate size, since, as we all know, furnaces and HIP vessels aren’t one size fits all!
Share how 3D printing or AM products/services help heat treaters.
Additive parts have become commonplace and we’re now regularly providing HIP, stress relief, and solution treating for them. A more interesting example is for parts printed in Inconel 718; we’ve developed a combined HIP and heat treat (or High Pressure Heat Treat) cycle which was able meet material properties specifications when the traditional processing techniques were not. This is where we feel the real cutting edge is when it comes to heat treatment of additive parts; the slow cooling HIP cycles developed for casting decades ago aren’t always optimal for today’s additive parts.
What changes have you made to accommodate the AM/3D printing marketplace?
Trevor Jones President Solar Manufacturing, Inc. Source: Solar Manufacturing, Inc.
There are several methods for 3D printing and we as heat treaters and vacuum furnace manufacturers generally classify those methods into two basic groups: those that use liquid binding polymers and those that do not.
For the group who does not use liquid binding polymers, there are no changes thus far to the design of the vacuum furnace that must be made. One significant caution is insuring there is no loose powder on the surface or cavities of the parts. Residual powder on or in the parts could have adverse effects on the parts themselves and to the vacuum furnace. The loose powder can liberate from the part during the heat treat or quench steps during the process and contaminate the vacuum furnace. The powder in the furnace is then considered FOD (foreign object debris) for subsequent heat treatments processed in that furnace. The powder could also accumulate over time and cause an electrical ground the heating elements or the quench motor, clog the heat exchanger, contaminate vacuum gauges and hot zone insulation, among other issues.
For the group that does contain liquid binding polymers, in addition to the comments about avoiding loose powder on or in the parts, care must also be taken to accommodate for the vaporization of the binder that occurs during heating of the parts. The binder, in its vapor form, will condense at cooler areas in the vacuum furnace. The condensed areas are potential contamination points and could have all the same issues and concerns of loose powder as described above. The binder collection locations, whether at intentional or non-intentional places, will also have to be routinely cleaned to maintain ideal binder collection, optimum vacuum pumping, and overall furnace performance.
How might your products and/or services change to accommodate this marketplace?
With the growth of 3D printing using liquid binder polymers, Solar Manufacturing has taken what was learned from the furnace modified at Solar Atmospheres of Western PA for MIM and AM processing and applied it to a new furnace product line specific for the debind and sinter applications. Solar Manufacturing collaborated with our affiliate company, Solar Atmospheres of Western PA, in modifying an existing vacuum furnace to accommodate the debind and sintering processes. A modified hot zone was installed, and a dedicated binder pumping port was added that helps minimize and target the condensation of detrimental binders evaporating out of parts containing binders. The modified Solar Atmospheres furnace is extremely valuable in gaining knowledge about various aspects of the process and learning what works, and what does not work, in furnace and recipe design. Combining the knowledge and experience of process development of Solar Atmospheres with the advanced Engineering Design Team at Solar Manufacturing, we believe we have a furnace design that modernizes and simplifies the debinding process while minimizing traditional maintenance issues.
Share how 3D printing or AM products/services help heat treaters.
We developed a process of debinding and sintering stainless steel parts with our affiliate company Solar Atmospheres in Souderton PA. The project started out with our Research and Development group to develop the process for the client’s parts. As the trials scaled up, test coupons became test parts, eventually full-size loads. There are always challenges to scaling up from test parts to production loads and we were able to provide the support the customer needed through that transition. The R&D eff orts were successful, and the client ended up purchasing multiple furnaces, which was the end goal for both parties.
Additionally, Solar Atmospheres is currently vacuum stress relieving a 3D component for a major U.S.-based aerospace company that is in use in aircraft today. Also, numerous large-scale components destined for deep space.
What do readers need to know about AM/3D to make decisions today?
Bob Hill, president of Solar Atmospheres of Western PA, reminded us to “realize and acknowledge that AM is still in its infancy stage. Therefore, many metallurgical uncertainties still exist for the multiple printing processes that exist. Understanding this new kind of metallurgy for each printing process, while developing standards and specifications unique to additive manufacturing, is still a huge obstacle. Until this is accomplished, AM will not be the ‘disruptive’ technology that all the experts predict it will be.” If your business is printing parts with liquid polymer binders, you should seriously consider how you plan on debinding and sintering the parts ahead of time. Printed parts in the “Green” or even “Brown” state are fragile and if you are going to ship the parts somewhere else for the debind and sinter steps, extreme care must be taken to prevent the parts from fracturing during transit. Although the shipping can be safely and successfully accomplished, ideally a furnace is available at the print shop to immediately perform the debind and sinter process to avoid those potential shipping difficulties. The other forms of 3D printing that do not contain liquid polymers generally do have this issue.
What changes have you made to accommodate the AM/3D printing marketplace?
Ben Gasbarre Executive Vice President Sales & Marketing Gasbarre Thermal Processing Systems
From our inception, Gasbarre has had expertise in the powder metallurgy industry, which requires debind and sinter applications similar to that in the AM and 3D printing markets. Our ability to supply equipment for both powder and parts producers has set us up for quick adoption into this market. While considerations need to be made specific to AM, our focus has been on technical support and helping the market grow to higher volume applications.
How might your products and/or services change to accommodate this marketplace?
As adoption of these technologies grow, the volume at which parts need to be produced will grow. Our line of continuous processing equipment in both vacuum and atmosphere applications are well suited. Whether it be debind and sinter, annealing, or stress relieving, we have equipment and expertise that can grow from early production to high volumes.
Share how 3D printing or AM products/services help heat treaters.
Overall, Gasbarre is here to be a resource and support the growth of the additive market. Whether that be through new equipment, servicing existing equipment, or involvement in the industry organizations, we have the expertise to drive success today and into the future!
What do readers need to know about AM/3D to make decisions today?
Additive manufacturing is such a dynamic technology, it is difficult to state one specific item. There is the potential for significant growth opportunities for new applications, but also the potential replacement of traditional manufacturing methods. We also know there is substantial backing for the technology by both private industry and government entities. Like other emerging technologies in the automotive and energies sectors, additive manufacturing isn’t a matter of if, but when it’ll achieve wide scale adoption and high-volume applications.
It is amazing how the list of materials being utilized with this technology is growing. While metals and alloys have not been the majority of the market, it is rapidly growing. With that growth, there is a wide variety of applications and thermal processing requirements for those materials. As well, the different additive and 3D printing processing methods (i.e., binder jetting, powder bed fusion, etc.) leads to a similar diversity in thermal processing requirements.
The powder metal industry continues to develop to keep up with production and industry needs. What exactly goes on with powdered metals and additive manufacturing? What is the sintering process? What should heat treaters know about the future of this industry?
In this original content article, three different resources -- an article, a radio broadcast, and a Heat TreatTVepisode -- come together to answer these questions and much more.
Ron Beltz Director of Strategic Accounts Bluestreak | Bright AM™
In this article, investigate the processes used to treat the metal powders. Sintering is one such process and others, like annealing and hot isostatic pressing, are examined too. Ron Beltz, director of strategic accounts at Bluestreak | Bright AM’s™ takes a look at these processes and also discusses other elements like software use and serialization. "One of the issues of additive manufacturing is the possibility of internal defects," Beltz explains. "Direct metal laser sintering (DMLS) regularly produces near 100% dense parts, but to provide another level of control to help reduce part failure, hot isostatic pressing (HIP), instead of heat treating, is successfully being used by many aerospace companies and in the casting industry."
Harb Nayar TAT Technologies (photo source: tat-tech.com)
Hear from Harb Nayar, president and CEO, TAT Technologies; as he peers into the future of the industry; "The other [change in industry] I think that’s going to emerge is most probably making more and more parts by powder metallurgy from metal powder which are 100% free alloyed." Nayar is confident that the powder metal industry will keep growing, and this interview gives good insights from his depth of knowledge.
John Engquist,FAPMI (past president of the Center for Powder Metallurgy Technology), gives some practical basics on what powder metallurgy (PM) is and how sintering helps produce automotive components. "Let's take a look at some PM applications: here we have a notch and pocket plate that are used in one way clutches. . . .made from sinter hardened steel and iron carbon steel. Here we have an automotive planetary carrier system. . . .Here we see stator cores for electric motors . . . ." Listen in on ways to use powdered metal.
These thought-provoking pieces give an opportunity dig a little deeper into sintering and additive manufacturing. Stay on top of education and developments within the powder metal industry.
Find heat treating products and services when you search on Heat Treat Buyers Guide.com
Ever heard of binder jetting (BJT)? It's an evolving technology that is quickly catching up to metal injection molding (MIM). Compared to MIM, BJT has a lower cost per part rate, produces larger parts, and, because BJT is a cold process, it does not introduce residual stress inside the part.
Even though BJT is a cold process, sintering is a key step in BJT. Read this best of the web article to learn the ins-and-outs of sintering with binder jetting.
An excerpt:
"Vacuum sintering furnaces are usually the go-to choice for sintering of [binder jetting] parts, thanks to the ability to provide bright and shiny sintered parts, the tight process parameters control and the possibility to work with different debinding and sintering atmospheres."
How do sintering parameters, especially the sintering atmosphere, affect the quality achievable from parts? Do you know what your three gas options are? Find out this and more, including an evaluation of some interesting solutions for your heat treating needs.
An excerpt:
"However vacuum furnaces operating with hydrogen require additional safety measures. For this reason, specific design solutions (such as double seals on all the furnace flanges) and software safeties are adopted. Despite the increased degree of complexity of the equipment and the higher process costs, vacuum furnaces operating with hydrogen over-pressure bring several advantages. . ."
Today’s story is an industry update coinciding with an excellent video resource describing conventional press and sintering with PM.Heat Treat TV seeks to provide helpful content on the latest trends in the industry and keep you current with what is happening between overlapping technologies. Read on to see how this great video relates to current trends.
If you have a video you’d like included on Heat Treat TV, please send an email to editor@HeatTreatToday.com and include a link to the video.
There has been a lot of talk in the industry about how sintering and powder metallurgy (PM) have been making headway in the world of heat treat. From how to use 3D printed green parts to understanding the step-by-step protocols of vacuum sintering, innovative heat treaters are envisioning new horizons at their fingertips, literally, by using the myriad of tools and skills at their disposal.
One of the most prominent figures, who is on the cutting edge of sintering, PM, and 3D printing in the North American market, is Harb Nayar, president and founder ofTAT Technologies LLC. Hespoke about some of the changes in these overlapping applications of 3D printing, sintering, PM, and additive manufacturing (AM). “Now, that ‘most probability low alloy steel,’ with even a lower amount of alloying, is going to be more conducive to faster quenching. In powder metallurgy – gas quenching is already used after sintering: they call it sinter hardening. In my opinion, heat treat will have to somehow modify its practices to deal with if the same forged product is really made from micro ingots as opposed to a macro ingot.”
This video highlights the questions of “what” and “how” of conventional press-and-sinter powder metallurgy. The creators of this excellent presentation are the Metal Powder Industries Federation’s Industry Development Board and John Engquist,FAPMI (past president of the Center for Powder Metallurgy Technology). Giving the very basics, they share that PM is just metal powder, molded by high pressure in a closed die, and that molded 3D green compacts are then sintered to produce parts in the various industries which service the automotive, recreation, agricultural, hydraulics, and other markets. Watch the video to see how this process breaks down, and what factors to consider (like size) when planning your PM use.
Additionally, this video is now available as the introduction video to Heat Treat Today’sSintering & Powder Metallurgy page where even more new and technological articles and videos are available.
A nickel-based heat resistant alloy that is very strong, corrosion resistant, and can be used at temperatures between -422°F and 1300°F has recently been released by a German specialist in custom prototypes and low-volume production parts.
Inconel 718 and Maraging Steel 1.2709 will expand Protolabs’ list of Direct Metal Laser Sintering (DMLS) materials that make up a wide range of metals available for rapid prototyping and the manufacture of functional end-use parts with complex geometries.
The high-temperature strength of Inconel 718 is derived from its ability to create a thick, stable passivating oxide layer at high temperatures, protecting the material from further attack. Inconel, which has good tensile, fatigue, creep and rupture strength, is thus ideal for the aerospace and heavy industries–particularly, in the production of jet engines, rocket engine components, gas turbine parts, instrumentation parts, power and process parts and related equipment that are exposed to extreme environments.
Photo credit/caption: Protolabs/Inconel 718 is a superalloy used in the development of turbojet engines for aircraft, among a variety of other applications.
Jude Pfingstler, President of Atlas Pressed Metals
Construction is underway at a powder metal and sintered parts manufacturing plant in Dubois, Pennsylvania, which will more than double the facility’s square footage and is intended to adapt to growth with the installation of new equipment, such as larger tonnage presses.
Atlas Pressed Metals, which manufactures complex and simple structural iron, sinter-hardened steel, stainless, copper, brass, and bronze components utilizing the pressed metal (also known as sintered metal and powder metal) process, partners with heat treatment providers in supplying powder metal components for the automotive, transportation, industrial equipment, and electric motors markets.
“New equipment for the addition will enable Atlas to grow our capacity in multi-level and higher tonnage equipment,” said Jude Pfingstler, president of Atlas Pressed Metals.
Construction begins for Atlas Pressed Metals in Dubois, PA
A Vermont-based ceramics solutions specialist and manufacturer recently announced in a white paper the introduction of a new direct-pressure, sintered silicon nitride powder-to-part component manufacturing process to be applied in a wide variety of industries.
Superior Technical Ceramics released the results of the heat treating process that provides a high-performance, cost-effective material solution as an alternative to both reaction-bonded silicon nitride and hot-pressed silicon nitride, and which the company expects to meet the demand from manufacturers looking for a material with a high strength-to-weight ratio, which compares favorably even with metallic nickel-based “superalloys”.
An excerpt:
“Silicon nitride (Si3N4) is a strong, lightweight, and commercially important non-oxide ceramic material. . . . Raw silicon nitride powder has a gray color and is typically fabricated by exposing pure metallic silicon powder to high-temperature nitrogen gas under pressure, although naturally occurring deposits have also been found as small inclusions in certain meteorites. Fully sintered (dense) silicon nitride has a dark gray to black coloration and component surfaces can be ground to a smooth polish. It is often utilized in demanding applications in which strength, wear resistance, fracture toughness, and dimensional stability are all required at high temperatures and/or in corrosive environments.”
Andrea Alborghetti, Technical Manager of TAV Vacuum Furnaces
Andrea Alborghetti, technical manager of TAV Vacuum Furnaces and contributor to the company’s blog, has provided a comprehensive, step-by-step overview of how to achieve “perfect vacuum sintering”, which includes an explanation of the metallurgic technologies involved; a review of debinding, “the first critical step of sintering”; and the factors to be taken into consideration when choosing what type of heat treatment process to use in order to obtain “a high quality of the end material in terms of density, porosity, and mechanical resistance.”
The powder metal industry continues to develop to keep up with production and industry needs. What exactly goes on with powdered metals and additive manufacturing? What is the sintering process? What should heat treaters know about the future of this industry? 
