一种新型镍基粉末高温合金的热压缩性能研究

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

摘要:

基于Gleeble热压缩模拟试验,研究变形温度和应变速率对一种新型第三代镍基粉末高温合金WZ-A3挤压态试样在变形温度1040~1130 ℃区间,应变速率0.01~0.0025 s_^-1 条件下的热压缩变形行为,分析了合金在不同热压缩条件下的晶粒尺寸及显微组织的变化。试验结果表明：WZ-A3合金挤压棒在1070~1100 ℃温度范围, 0.01~0.005 s_^-1 应变速率范围内热压缩变形后可以获得约4.5 μm细小均匀的晶粒组织,各部位均未出现项链晶及异常晶粒长大的现象。根据以上试验条件成功制备了两件直径190 mm高97 mm的小尺寸热模锻试验盘,验证了WZ-A3合金的热压缩性能。

关键词:镍基粉末高温合金;热压缩变形;晶粒度;显微组织

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