激光选区熔化Ti6Al4V在介观尺度下的热力学行为与缺陷:数值模拟与实验验证  

Thermodynamic Behavior and Defects of Laser Selective Melting Ti6Al4V at Mesoscopic Scale:Numerical Simulation and Experimental Verification

作　　者：赵金猛 卢林 王静荣[3] 张亮 吴文恒 朱冬[1,2,3] 郭帅东 肖从越[1,2] ZHAO Jinmeng;LU Lin;WANG Jingrong;ZHANG Liang;WU Wenheng;ZHU Dong;GUO Shuaidong;XIAO Congyue(Shanghai Engineer Research Center of 3D Printing Materials,Shanghai 200437,China;Shanghai Research Institute of Materials,Shanghai 200437,China;College of Engineering,Shaghai Polytechnic University,Shanghai 201209,China)

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

出　　处：《材料导报》2021年第S02期410-416,共7页Materials Reports

基　　金：上海市青年科技英才扬帆计划资助项目(17YF1405400);上海市青年科技启明星计划资助项目(18QB1400600)。

摘　　要：本工作基于介观尺度激光选区熔化三维Ti6Al4V粉末床模型,研究了激光选区熔化工艺参数对成形件内部冶金缺陷的影响,结果表明:当激光功率从100 W提高到350 W时,熔池的宽度从62.6μm提高到116.2μm,深度从24.9μm提高到32.4μm。当激光能量不足以穿透粉末层时,熔池中存在未熔颗粒并产生球化现象。当激光功率过高时,金属粉末在充足的能量下发生蒸发,从而产生反冲压力提高了熔体的飞溅能力,导致熔池表面质量下降。根据模拟的工艺制备了成形件并进行了实验,结果中孔隙率与熔池宽度的实验结果与模拟结果相符,表明本工作基于介观尺度的粉末床非连续界面模型可以用于指导工艺参数的选取以及激光选区熔化内部冶金缺陷的控制。Based on the three⁃dimensional Ti6Al4V powder bed model for selective laser melting at mesoscopic scale,the influence of selective laser melting parameters on the internal metallurgical defects of formed parts was studied.With the laser power is increased from 100 W to 350 W,the width of molten pool increases from 62.6μm to 116.2μm,the depth increases from 24.9μm to 32.4μm.When the laser energy is not enough to penetrate the powder layer,unmelted particles and spheroidization exist in the molten pool.When the laser power is too high,the metal powder will evaporate under sufficient energy,resulting in recoil pressure,which improves splashing ability of the melt and decreases the surface quality of molten pool.According to the simulation process,the forming parts were prepared and tested,the experimental results of porosity and molten pool width are consistent with the simulation results,which indicates that the discontinuous interface model of powder bed based on mesoscopic scale could be used to guide the selection of process parameters and control metallurgical defects in selective laser melting.

关 键 词：激光选区熔化(SLM) TI6AL4V 介观尺度 数值模拟 工艺参数 冶金缺陷 

分 类 号：TG111[金属学及工艺—物理冶金] TP391.9[金属学及工艺—金属学]