选区激光熔化(SLM)成型过程中经常在零件表面和多边形的角上出现凸点的零件缺陷问题, 这种情况很大程度上就是激光振镜在扫描线交点处的延时处理问题所导致的。为了解决这个问题, 通过对振镜系统的运动方式和延时模型原理分析, 借助仿真软件建立有限元模型, 模拟激光扫描过程, 分析振镜延时对于试件温度场和应力场变化的影响。实验结果表明, 激光扫描过程中, 振镜在扫描线转向处采用适当延时处理机制, 能够很好的减少颗粒凸起与坑洼的数量, 改善成型件表面质量。

Defects of part bump occurs in the surface and on the corner of polygon during the process of Selective Laser Melting ( SLM ). To a large extent this kind of situation is related to the way that the scanner use to deal with the delay problems occur in the scanning line at the intersection. To solve the problem, through the analysis of the motion mode and delay model of the scanner, the finite element model is established by simulation software, and the laser scanning process is simulated to analyze the influence of the delay of the scanner on the temperature field and stress field of the part. It is found that scanner can reduce the number of pellets and potholes and improve the surface quality of the modeled part by using appropriate delay method at the turning of the scanning line during the laser scanning process.