增材制造用W-Nb合金粉末的制备与应用  

Preparation and Application of W-Nb Alloy Powder for Additive Manufacturing

作　　者：杨广宇[1] 贾文鹏[1] 贾亮[1] 刘楠[1] Yang Guangyu;Jia Wenpeng;Jia Liang;Liu Nan(State Key Laboratory of porous Metal Materials,Northwest Institute for Nonferrous Metal Research,Xi'an 710016,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

出　　处：《稀有金属》2023年第10期1453-1459,共7页Chinese Journal of Rare Metals

基　　金：国防科工局科学挑战专题项目(TZ2018006);陕西省重点研发计划项目(2021KW-34);国家自然科学基金项目(51627805)资助。

摘　　要：结合钨合金的特性及增材制造过程对粉末均匀性、稳定性的要求,以微米级球形钨粉和纳米级铌粉为原料,采用行星球磨工艺制备了可用于增材制造的W-Nb复合型粉末,利用球磨过程中的作用力,将纳米粉末分散并均匀吸附在球形钨粉表面,形成面包覆结构;分析了球磨时间对粉末形貌及物理性能的影响。结果表明,随着球磨时间的延长粉末主要发生以下变化:(1)球形钨粉形貌不变,纳米铌粉之间存在明显的团聚;(2)球形钨粉形貌不变,纳米铌粉充分分散且在球形钨粉表面吸附;(3)吸附在球形钨粉表面的铌粉之间发生一定的冷焊,球形钨粉表面开始出现破损;(4)铌在钨中发生一定的固溶,但是球形钨粉大量破损。采用粉床型电子束增材制造技术对复合粉末的工艺适应性进行了验证,复合粉末铺展均匀、稳定,成形样品成分均匀,晶界处不存在明显的铌元素富集。Chemical composition, particle size distribution, fluidity, bulk/tap density and morphology of the powder material have an important effect on the process of powder bed based additive manufacturing. Spherical metal powders are usually used as raw material in additive manufacturing process. Gas atomization(GA) and plasma rotating electrode(PREP) are familiar ways in the preparation of spherical powders, However, due to the high melting point of tungsten alloy, the preparation of pre-alloy powder is difficult in these ways. In this study, W-Nb alloy powder for additive manufacturing was prepared by planetary ball milling with micro-size spherical W powder and nano-size Nb powder. The effect of milling time on powder morphology and physical properties was analyzed. Additive manufacturing of selective electron beam melting(SEBM) technology was used to verify the adaptability of the powder for additive manufacturing. XRD spectrum of W-Nb composite powder showed the existence of W and Nb at the same time. With the extension of milling time, the diffraction peak of W gradually widened. When the milling time reached 36 h, the diffraction peak of W shifted to high angle.The broadening of the diffraction peak was mainly due to the severe impact of the ball on the powder during ball milling, resulting in micro deformation on the surface of the powder and the refinement of grain. At the same time, according to the Bragg equation, it could be inferred that after long-time ball milling, Nb with larger atomic radius began to dissolve into W matrix, resulting in the right shift of diffraction peak. The particle size distribution, sphericity and symmetry of the powder showed that milling has little effect on the overall distribution of particle size. However, ball milling had an obvious effect on the sphericity and symmetry of the powder. With the increase of milling time, the sphericity and symmetry of the powder decreased, and they decreased significantly at 24 h, then tended to be stable. It was found by analyzing the powder m

关 键 词：增材制造 粉末原料 钨基合金 W-Nb合金 

分 类 号：TG146.411[一般工业技术—材料科学与工程]