This disclosure relates to making components by powder metallurgy. Powder metallurgy is often used to manufacture articles, such as disks, shafts and the like, for gas turbine engines. For example, a metallic powder of a desired composition is consolidated and then forged into the final or near-final shape of the article.
To improve the mechanical properties of the article after forging, such as fatigue, strength, creep, and the like mechanical properties, the article can be subsequently heat treated to produce a grain size within a desired target range. A challenge in achieving the desired target grain size range is that the article may include areas of non-homogenously stored energy from the forging step. This uncontrolled stored energy can cause an abnormal or critical grain growth beyond the desired target range during the heat treatment step. As a result, the parameters of the forging step are typically tightly controlled and the complexity of the shape of the article is limited, to homogenize the level of stored energy though the part and therefore to reduce the abnormal grain growth.
USPTO Backgrounds
USPTO Backgrounds