Evaluation of Hot Compression Behavior of a Novel Ni-based PM Superalloy

Abstract:

A novel third generation Ni-based PM (Powder Metallurgy) superalloy WZ-A3 has been evaluated for its hot compression behavior. Gleeble simulation tests on the extruded WZ-A3 samples over the temperature range of 1040~1130 ℃ and strain rate range of 0.01~0.0025 s_^-1 have been conducted. The samples compressed at different conditions were analyzed for grain size and microstructure evolution. The results indicate that under the compression conditions of temperatures from 1070 ℃ to 1100 ℃, and strain rate from 0.01 s_^-1 to 0.005 s_^-1, a uniform fine grain structure around 4.5 μm can be obtained. No abnormal grain growth and necklace grains were observed throughout. To validate compression property of the extruded WZ-A3 alloy, Hot die forging was conducted successfully to make two prototype forgings of the size of 190 mm in diameter and 97 mm in height.

Key words:Ni-based powder metallurgy superalloy; hot compression; grain size; microstructure