层间扫描策略对SLM直接成型金属零件质量的影响

Impact of inter-layer scan strategy on quality of direct fabrication metal parts in SLM process

为了通过选区激光熔化技术直接快速成型高致密度及高表面质量零件,采用正交试验对316L不锈钢粉末进行了光纤激光选区熔化成型研究,分析了正交实验中存在的扫描线间搭接缺陷及零件外边凸起缺陷,随后"层间错开"扫描策略因为更好的扫描线间润湿效果及成型效率而被应用于实验中,进行扫描线间搭接情况及层间熔接情况显微观察。层间层内扫描线具有良好的冶金结合,孔隙率大大减少,获得了高致密化的成型效果;使用优化的工艺参量与扫描策略成型具有空间曲面的个性化手术模板,硬度与致密度分别达HV_(0.3)250和95.8%。结果表明,层间扫描策略对选区激光熔化技术直接成型金属零件成型效果良好。

In order to manufacture high density parts with high quality surface by means of selective laser melting technique, orthogonal test method was applied to investigate fiber laser selective laser melting of 316L stainless steel powder. Defects among scan lines and protuberance of outside frame of samples were found in the experiments, which were great impediments for part quality improvement. Then, ＂inter-layer stagger＂ scan strategy was applied for its better wetting ability and fabrication efficiency. Bonding quality among scan lines and layers was analyzed by means of micro-observing and fewer holes were found and better metallurgical bonding and higher density were achieved. Finally, optimized process parameters and ＂interlayer stagger＂ scan strategy were applied to manufacture customized orthopedics model, its micro-hardness and relative density were HV0.3 250 and 95. 8% respectively. Results show that inter-layer scan strategy has fine effect on the quality of direct fabrication metal parts in selective laser melting process.