Source: Multiple (see below)

You may know it by one name — Precipitation Hardening, or by another — Age Hardening, or Particle Hardening. Whatever term you use, if you are employing this process to strengthen aluminum, titanium, or forms of alloys, the right balance between material and application will bring you the right results.

Precipitation hardening is a heat treating method used to strengthen metal components through the utilization of controlled release of solid impurities — or precipitates — to form precipitate clusters.

“The formation of these precipitates is accomplished by using a solution treatment at high temperatures prior to a rapid cooling process. The solution heat treatment results in a single-phase solution while the rapid cooling results in a stable material by preventing the creation and propagation of lattice defects. This greatly strengthens the metal matrix. 

Precipitation hardening is typically performed in a vacuum, inert atmosphere at temperatures ranging from between 900º and 1150° F. The process ranges in time from one to four hours, depending on the exact material and the characteristics specified.” ~ The Balance

The process generally follows three steps (per AZO Materials):

1. Solution treatment at high temperatures
2. Rapid cooling
3. Heat treatment to induce precipitation

According to Bodycote’s website, where more information is given regarding the process details, the outcome varies depending upon whether a solution treating-only method is used or a combination of solution treating and precipitation age hardening.

 

Read more about the types of metals treated by precipitation hardening, techniques, industrial applications, and more:

“Learn About Precipitation Hardening” (The Balance)

“Age Hardening – Metallurgical Processes” (AZO Materials)

“Precipitation Hardening: Stainless Steels” (Bodycote)

 

Photo credit: Bodycote