Microstructure of Selective Laser Melting Parts Under Different Scanning Strategies
ZHAO Xue1, HE Ketai1, LI Huaixue2
1. School of Mechanical Engineering, University of Science and Technology Beijing, Beijing 100083, China;
2. AVIC Manufacturing Technology Institute, Beijing 100024, China
A multi-track finite element model was developed to simulate melt pool contours and the temperature field during selective laser melting (SLM) of 316L stainless steel powder under different scanning strategies. Considering, the thermophysical properties changes with temperature and the influence of latent heat of phase. The simulated temperature field was compared with experimental measurements results. Furthermore, the presented results established a correlation between the scanning path and the microstructure of SLM specimens. The simulation results showed that as the scanning tracks increase, the maximum temperature of melt pool rises slightly. The molten pool contains a large number of columnar crystals that grow vertically along the direction of the maximum temperature gradient. In addition, microscopic defects are more likely to occur at the junction between scanning islands, where the heat and stress are concentrated. Besides, the scanning strategy affects the microstructure and microhardness of SLM parts, and the part under the spiral strategy had finer grains and higher Vicker hardness than that formed under spiral-island strategy.
赵雪,贺可太,李怀学. 扫描策略对选区激光熔化零件微观组织的影响[J]. 航空制造技术, 2019, 62(1/2): 64-71.
ZHAO Xue, HE Ketai, LI Huaixue. Microstructure of Selective Laser Melting Parts Under Different Scanning Strategies. Aeronautical Manufacturing Technology, 2019, 62(1/2): 64-71.