基于预合金粉末原料的粉床型电子束增材制造W-Ni-Fe-Co合金研究  

Research on W-Ni-Fe-Co Alloys Fabricated by Selective Electron Beam Melting from Pre-alloyed Powder

作　　者：杨广宇[1] 陈靖海 刘楠[1] 杨坤[1] 贾亮[1] 贾文鹏[1] 王建[1] 汤慧萍[1] Yang Guangyu;Chen Jinghai;Liu Nan;Yang Kun;Jia Liang;Jia Wenpeng;Wang Jian;Tang Huiping(State Key Laboratory of Porous Metal Materials,Northwest Institute for Nonferrous Metal Research,Xi’an 710016,China;Northeastern University,Shenyang 110819,China)

机构地区：[1]西北有色金属研究院金属多孔材料国家重点实验室,陕西西安710016 [2]东北大学,辽宁沈阳110819

出　　处：《稀有金属材料与工程》2020年第11期3865-3869,共5页Rare Metal Materials and Engineering

基　　金：科学挑战专题(TZ2018006);国家重点研发计划项目(2016YFB0700301)。

摘　　要：采用等离子旋转雾化方法制备了W-Ni-Fe-Co预合金粉末,并进行了粉床型电子束增材制造成形。结果表明:W-Ni-Fe-Co预合金粉末由2种形貌的颗粒组成,一是球形粉末颗粒,二是由许多小颗粒粘结而成的不规则粉末颗粒。预合金粉末内部显微组织为γ-(Ni-Fe)相内部镶嵌着规则的W颗粒,γ-(Ni-Fe)相内部含有过饱和的W元素。在粉床型电子束增材造成形过程中,W-Ni-Fe-Co合金的显微组织显示出一定的遗传性,但是由于成形过程中细小的熔池会同时受到反冲压力、热毛细管力及马兰戈尼对流的作用,熔池的瞬时流动剧烈,促进了钨颗粒的重排过程,显微组织更为均匀。成形致密化过程主要为W颗粒的重排,并没有显著的W的溶解-析出过程。粉床电子束增材造成形的W-Ni-Fe-Co合金室温抗拉强度可达1098 MPa,但是合金塑性较差,断裂方式主要为钨的穿晶断裂和周围γ-(Ni-Fe)相的韧性撕裂。W-Ni-Fe-Co pre-alloyed powder was prepared by plasma rotating electrode process,and then selective electron beam melting(SEBM)was performed.Results show that W-Ni-Fe-Co pre-alloy powder consists of spherical powders and irregular powders with the microstructure of tungsten particles coated byγ-(Ni-Fe)phase,which contains supersaturated tungsten.Microstructure of the W-Ni-Fe-Co alloy shows certain heredity from powder to SEBMed sample.Since the molten pool is subjected to recoil pressure,hot capillary force and Marangoni convection during SEBM,the instantaneous flow of the molten pool promotes the rearrangement of tungsten particles,leading to a higher uniformity in the SEBM sample than in the powder.Densification process during SEBM is mainly the rearrangement of W particles,and there is no significant dissolution-precipitation process of W.The tensile strength of SEBMed W-Ni-Fe-Co alloy is measured to be 1098 MPa together with a poor ductility.Fracture mode is brittle transgranular fracture of tungsten and ductile tearing ofγ-(Ni-Fe)bonding phase.

关 键 词：增材制造 电子束选区熔化成形 高比重钨基合金 W-Ni-Fe-Co合金 

分 类 号：TG146.411[一般工业技术—材料科学与工程]