母合金法MIM418涡轮的近终成形与致密化机理  

Net-shape forming and densification mechanism of MIM418 turbine wheel using master alloy method

作　　者：陈晓玮 刘烨 章林 曲选辉 CHEN Xiaowei;LIU Ye;ZHANG Lin;QU Xuanhui(Institute for Advanced Materials and Technology,University of Science and Technology Beijing,Beijing 100083,China;School of Materials Science and Engineering,Xiangtan University,Xiangtan 411100,China)

机构地区：[1]北京科技大学新材料技术研究院,北京100083 [2]湘潭大学材料科学与工程学院,湖南湘潭411100

出　　处：《中南大学学报（自然科学版）》2020年第11期2999-3006,共8页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51604240,51974029);湖南省自然科学基金资助项目(2019JJ50585)。

摘　　要：以母合金粉末和羰基镍粉为原料,采用母合金法制备MIM418高温合金,并通过注射成形实现增压涡轮的近终成形。研究结果表明:通过真空烧结与热等静压,MIM418涡轮相对密度达到99%以上。对烧结态的合金显微组织进行表征,发现γ'相形貌和大小均匀,为0.5μm左右。在烧结过程中产生了瞬时液相,液相中主要合金元素为Cr,在等温凝固后演变为晶界碳化物。瞬时液相的出现大大促进了致密化与扩散均匀化过程。母合金法MIM418合金的抗拉强度、屈服强度分别为931 MPa和788 MPa,比铸造K418合金的抗拉强度和屈服强度分别提高了48%和126%。Using master alloy powder and carbonyl Ni powder as raw materials,MIM418 superalloy was prepared through master alloy approach,and near-net shape forming of MIM418 turbine wheel was realized by metal injection molding.The results show that through vacuum sintering and hot isostatic pressing,the relative density of MIM418 turbine wheel is up to 98%.The morphology and size ofγ'phase are uniform and the size ofγ'phase is about 0.5μm.The transient liquid phase is generated in the sintering process.The main alloying element in the liquid phase is Cr,which transforms to the carbides along grain boundaries after isothermal solidification.The appearance of transient liquid phase greatly promotes the densification and diffusion process.The tensile strength and yield strength of MIM418 turbine using the parent alloy method are 931 MPa and 788 MPa,respectively,which are 48%and 126%higher than those of casted K418 alloy.

关 键 词：MIM418高温合金 母合金法 金属注射成形 力学性能 

分 类 号：TF12[冶金工程—粉末冶金]