镍基粉末冶金高温合金中γ′相形态不稳定性研究  

MORPHOLOGICAL INSTABILITY OFγPHASE IN NICKEL-BASED POWDER METALLURGY SUPERALLOYS

作　　者：胡本芙[1] 刘国权[1,2] 吴凯[1] 田高峰[1] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]北京科技大学新金属材料国家重点实验室,北京100083

出　　处：《金属学报》2012年第3期257-263,共7页Acta Metallurgica Sinica

基　　金：国家预研基金项目9140A12070507QT0202;国家高技术研究发展计划项目2007AA03A223资助~~

摘　　要：较系统地研究了低错配度FGH98I和FGH96合金在热处理条件下γ′相的形态演化行为.结果表明:γ′相的形态失稳形式可归纳为γ′相分裂和γ′相不稳定长出形态,γ′相分裂主要是γ/γ′相间弹性应变场的各向异性和溶质元素富集相互作用造成,而形状不规则的不稳定长出形态主要是由于基体或晶界局部溶质原子浓度(或过饱和度)变化导致γ′相的非平衡性生长,讨论了γ′相分裂和不稳定长出形态同时发生现象,及不连续脱溶析出导致扇形结构的形成机理.The morphological evolution and its regularity ofγ′precipitates in the low mismatch alloys powder metallurgy（P/M） FGH98I and FGH96 under different heat treatment conditions were studied systematically.The results show that the morphological instability ofγ′phase can be summarized as the splitting and unstable protrusion.The splitting ofγ′phase is caused by the interaction of anisotropic elastic strain field betweenγ′phase andγmatrix which is rich in solute atoms.While the irregular morphology of unstabe protrusion is mainly due to the concentration changes of solute atoms in the matrix or in the local places along grain boundaries,leading to the non-equilibrium growth ofγ′phase.The coexist phenomenon of splitting and unstable protrusion,the formation mechanism of fan type structure induced by discontinous precipitation are discussed respectively.

关 键 词：镍基粉末高温合金 γ'相 析出 错配度 

分 类 号：TF125.2[冶金工程—粉末冶金]