粉末原料对粉床型电子束增材制造高比重钨基合金成形过程的影响  

Selective Electron Beam Melting(SEBM) of Tungsten Heavy Alloys with Mixed and Pre-Alloy Raw Powder

作　　者：杨广宇[1] 陈靖海 刘楠[1] 杨坤[1] 贾亮[1] 贾文鹏[1] Yang Guangyu;Chen Jinghai;Liu Nan;Yang Kun;Jia Liang;Jia Wenpeng(State Key Laboratory of Porous Metal Materials,Northwest Institute for Nonferrous Metal Research,Xi'an 710016,China;School of Material Science and Engineering,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]东北大学材料科学与工程学院,辽宁沈阳110819

出　　处：《稀有金属》2022年第11期1422-1428,共7页Chinese Journal of Rare Metals

基　　金：国防基础科研核科学挑战专题项目(TZ2018006)资助。

摘　　要：分别以混合元素粉末和预合金粉末为原料进行了W-Ni-Fe系高比重钨基合金的粉床型电子束增材制造工艺研究。分析了粉末原料的类型对合金的致密化过程和显微组织的影响。实验结果表明:混合元素粉末在铺展过程中受粉末团聚或重力作用的影响,极易出现成分偏析,导致成形试样致密度低且显微组织不均匀,预合金粉末更能保证成形过程中粉末的均匀性和成形的稳定性。两种类型的粉末在成形过程中的致密化过程有所不同。混合元素粉末的致密化过程主要为:低熔点相熔化→钨颗粒在低熔点液相中的重排→钨颗粒的溶解-析出,由于细小熔池的熔化凝固过程快,钨在液相中大量溶解,但是来不及充分析出便已凝固,溶解-析出过程中钨的溶解占主导。而在预合金粉末中,低熔点相中钨已达到过饱和状态,以此粉末为原料进行成形,成形过程中钨的溶解-析出过程微弱,致密化过程主要是钨颗粒的重排。Additive manufacturing is a method of building parts by the continuous accumulation of materials. This technology makes the building of complex parts possible and has been widely used in the forming of complex alloy components such as titanium alloy,aluminum alloy,superalloy and stainless steel. Tungsten based alloys with the characteristics of high density,high strength,high conductivity,high coefficient of thermal expansion,good corrosion and oxidation resistance,are widely used in aerospace,electronics,chemical industry,nuclear industry and other fields. Compared with other alloys,tungsten based alloys have some particularity:firstly,the melting points of the elements vary greatly(W:3400 ℃,Ni:1450 ℃,Fe:1530 ℃,Co:1490 ℃). Secondly,the density of the elements varies greatly(W:19.3 g·cm-3,other low melting point element:7.2~8.9 g·cm-3). At present,the raw materials used in the report on additive manufacturing tungsten-based alloy were mostly mechanical mixed powder. But powder based additive manufacturing process is a dynamic process of continuous flowing and spreading of powder,the uniformity and stability of raw powder are the main premise for the quality of the as-build parts. At present,seldom research was done on the adaptability of powder raw materials to the manufacturing process of tungsten-based alloy. In this study,additive manufacturing of selective electron beam melting(SEBM)process of W-Ni-Fe alloy was studied with mixed powder and pre-alloy powder as raw materials. The effect of raw material on the microstructure and densification process of W-Ni-Fe alloy during SEBM process were analyzed. The mixed powder was prepared by mechanical ball milling with the milling medium anhydrous ethanol. The mass ratio of tungsten,nickel and iron was 90∶7∶3. According to the particle size of tungsten powder,the mixed powder is divided into mixed Powder 1 and 2. The tungsten powder used in mixed Powder 1 was prepared by reduction method with the particle size 2~5 μm,The tungsten powder used in the mixe

关 键 词：高比重钨基合金 W-NI-FE合金 增材制造技术 粉床型电子束增材制造(SEBM) 

分 类 号：TG164.4[金属学及工艺—热处理]