工艺参数对激光选区熔化成形Ti6Al4V合金致密性的影响  

Effect of Process Parameters on Compactness of Ti6Al4V Alloy Formed by Laser Selective Melting

作　　者：赵金猛 卢林[1] 王静荣 张亮[1] 吴文恒[1] ZHAO Jinmeng;LU Lin;WANG Jingrong;ZHANG Liang;WU Wenheng(Shanghai Research Center of Materials Engineering for Additive Manufacturing,Shanghai Research Institute of Materials,Shanghai 200437,China;College of Engineering,Shanghai Polytechnicv University,Shanghai 201209,China)

机构地区：[1]上海材料研究所上海3D打印材料工程技术研究中心,上海200437 [2]上海第二工业大学工学部,上海201209

出　　处：《机械工程材料》2022年第8期100-104,共5页Materials For Mechanical Engineering

基　　金：上海市青年科技英才扬帆计划项目(17YF1405400);上海第二工业大学研究生项目基金资助项目(EGD19YJ0093);上海市青年科技启明星计划项目(18QB1400600)。

摘　　要：采用激光选区熔化技术制备Ti6Al4V合金,通过正交试验方法研究了激光功率、扫描间距和铺粉厚度对合金致密性的影响,并探讨了孔隙缺陷的形成机理。结果表明:铺粉厚度对成形合金相对密度的影响最大,扫描间距次之,激光功率的影响最小;合金的相对密度随激光功率的增加先增大后趋于稳定,随扫描间距和铺粉厚度的增加而减小,随体能量密度的增加而增大;最优工艺为激光功率200 W、扫描间距0.10 mm、铺粉厚度0.03 mm,此时合金的相对密度为99.24%;合金内部存在气孔和匙孔两种孔隙,前者主要由熔池内部较高的温度梯度造成设备内部的惰性气体、粉末蒸气等未及时逸出所导致,后者主要由工艺参数不当,熔池发生球化效应以及皱缩效应所引起。Ti6 Al4 V alloy was prepared by selective laser melting technique. The effects of laser power, scanning hatch and powder thickness on the compactness of the alloy were studied by orthogonal experiment method, and the formation mechanism of hole defects was discussed. The results show that the powder thickness had the greatest influence on the relative density of the formed alloy, followed by the scanning hatch, and the laser power had the least influence. The relative density of the alloy increased first and then tended to be stable with increasing laser power, decreased with increasing scanning hatch and powder thickness, and increased with increasing bulk energy density. The optimal process was laser power of 200 W, scanning hatch of 0.10 mm and powder thickness of 0.03 mm, at this time the relative density of the alloy was 99.24%. The alloy existed two kinds of hole, including pores and keyholes;the former was mainly caused by the inert gas inside the equipment and powder vapour not escaping in time due to the high temperature gradient inside the molten pool;and the latter was mainly caused by spheroidize and shrink effect of molten pool due to improper process parameters.

关 键 词：激光选区熔化 相对密度 孔隙 TI6AL4V合金 

分 类 号：TB31[一般工业技术—材料科学与工程] TF121[冶金工程—粉末冶金]