中间处理对粉末高温合金FGH4095组织性能的影响

为了研究热处理制度对粉末高温合金FGH4095组织强化相γ'形态分布特征的影响,采用氩气雾化制备FGH4095高温合金粉末,经筛分、除夹杂处理后,热等静压烧结成形,对比研究不同的热处理条件下, FGH4095合金组织γ'相的大小、形貌及分布,测试了室温20 ℃和高温650 ℃下合金的拉伸性能,并对650 ℃高温下拉伸断口进行了比较分析.结果表明:中间热处理能够改善γ'相的形状及分布;经中间处理,材料高温拉伸性能明显提高,屈服强度从1 150 MPa提高到1 210 MPa,拉伸强度从1 230 MPa提高到1 460 MPa;中等尺寸γ'相数量增加,晶界得到优化,合金高温塑性得到提高. 

Effect of Intermediate Heat Treatment on Microstructure and Properties of FGH4095 Superalloy

In order to study the effect of heat treatment on the distribution characteristics of γ' strengthening phase in powder metallurgy superalloy FGH4095, the FGH4095 superalloy powders were prepared by argon gas atomization. After powder screening and inclusion removal, compacts were formed by hot isostatic pressing (HIP) sintering. Then the size, morphology, and distribution of the γ' strengthening phases were analyzed for the superalloy specimens subjected to different heat treatments; the tensile properties at 20℃ and 650℃ were tested; and the instant fracture microstructures at 650 ℃ were compared. The results show that intermediate heat treatment processes could improve the distribution and shape of the γ' phase. After the intermediate heat treatment, the high-temperature (650 ℃) tensile performances improved obviously: the yield strength σ0.2 increased from 1 150 to 1 210 MPa, and the tensile strength σb increased from 1 230 to 1 460 MPa. The intermediate heat treatment increased the total number of the middle γ' phase, optimized grain boundaries, and improved the high temperature plastic property of the alloy.