摘要
以氩气雾化法制备的镍基高温合金FGH96粉末为原料,采用放电等离子烧结(spark plasma sintering,SPS)工艺制备FGH96高温合金,同时在与SPS工艺相同条件下对原料粉末进行热处理,并采用热等静压(hot isostatic pressing,HIP)工艺制备FGH96高温合金,通过分析在不同SPS温度或不同保温时间下合金的微观组织与晶粒尺寸以及对比热处理后的粉末和热等静压合金的晶粒取向与晶粒尺寸,研究SPS镍基粉末高温合金的组织特征。结果表明,合金在SPS 40 min后达到高度致密。烧结温度为1 070℃时,合金的显微组织为细小的胞晶和枝晶组织,碳化物析出相主要分布在晶粒内部、少量分布在晶界上,未观察到明显的原始颗粒边界(priorparticleboundaries,PPBs)。烧结温度为1 170℃时,合金的显微组织为等轴晶晶粒,碳化物析出相沿PPBs分布,且存在明显的PPBs。放电等离子烧结工艺能在一定程度上消除原始颗粒边界,但改善合金晶粒尺寸的作用不明显。
Nickel-base superalloys were sintered by spark plasma sintering(SPS)using the powders of FGH96 fabricated by argon vaporization method as raw material.At the same time,the raw material powder was heat-treated under the same conditions as the SPS process,and the FGH96 superalloy was prepared by hot isostatic pressing(HIP).By analyzing the microstructure and grain size of the alloy at different sintering temperatures or different heat preservation time,the grain orientation and grain size of the alloy fabricated by HIP with heat treatment powder were compared,and the microstructure characteristics of SPS Ni-based superalloy were studied.The results show that the alloy is nearly densified after sintering for 40 min.While the microstructure of the alloy is composed of tiny cellular structure and dendrite crystals when sintered at 1 070℃.The carbide precipitates distribute mainly inside the grains with a few on the grain boundaries,which results in almost invisible PPBs.The microstructure of the alloy is composed of equiaxed grains when sintered at 1 170℃.The carbide precipitates distribute along the prior particle boundaries,which make quite obvious PPBs.It is indicated that the method of SPS can reduce the PPBs in certain degree,but it had no effect on control the grain size.
作者
秦子珺
刘锋
江亮
QIN Zijun;LIU Feng;JIANG Liang(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,PR China;Powder Metallurgy Research Institute,Central South University,Changsha 410083,China)
出处
《粉末冶金材料科学与工程》
EI
北大核心
2018年第5期488-494,共7页
Materials Science and Engineering of Powder Metallurgy
基金
国家自然科学基金资助项目(51401242
51301209)
研究生自主探索项目(2016zzts268)
关键词
镍基高温合金
粉末冶金
放电等离子烧结
原始颗粒边界
晶粒尺寸
Nickel-based superalloys
powder metallurgy
spark plasma sintering(SPS)
prior particle boundries(PPBs)
grain size
