选择性激光熔化W-Re合金成形工艺与性能研究

Forming Processes and Properties of Selective Laser Melted W-Re Alloy

由于钨(W)的高熔点等固有特性,获得高致密度的W及W合金制件一直是个难题。采用不同方法研究了W-Re合金的选择性激光熔化中工艺参数调整及铼(Re)加入的条件对成形试样致密度、微观形貌以及力学性能的影响。结果表明,一定工艺参数范围内,W-Re合金制件的致密度与激光功率成正比,与扫描速度成反比。且当激光功率为180 W,扫描速度为600 mm/s,扫描间距为0.03 mm时,致密度达到了最大值96.1%。通过优化工艺参数,减少了孔洞的出现,达到了细晶强化,使得最高硬度达到550 HV。分析物相可知,Re的置换固溶使W衍射峰发生向右偏移,在高温下,Re对W起到固溶强化作用。对比纯W与W-Re合金可以发现,加入Re后,选择性激光熔化W-Re合金试样的致密度、硬度及裂纹的大小和形态均优于纯W试样。

Owing to the high melting point of tungsten(W),achieving high-density W and W alloy components is challenging.In this study,different methods were used to study the effects of process parameter adjustment and Re addition conditions on the density,microstructure,and mechanical properties of W-Re alloys.Results show that the density of the W-Re alloy is directly proportional to the laser power and inversely proportional to the scanning speed.When the laser power was 180 W,the scanning speed,scanning interval,and maximum density are 600 mm/s,0.03 mm,and 96.1%,respectively.The process parameters were optimized to reduce pore formation and achieve fine-grain strength,realizing the maximum hardness of 550 HV.The displacement solution of Re induces a right shift of the diffraction peak of W.At high temperatures,Re can strengthen the solution of W.The density,hardness,crack size,and morphology of the selective laser melted W-Re alloy are better than those of the pure W alloy.