选区激光熔化不锈钢全流程关键问题研究现状与进展

选区激光熔化(SLM)是制造精度最高的金属增材制造工艺，用于制造复杂几何形状的金属零件。316L不锈钢具有面心立方结构，在从熔融态冷却至室温的过程中通常不发生固态相变，基于这种特性，316L不锈钢成为SLM中应用最广泛的金属材料。与传统工艺相比，SLM工艺虽然能够生产高致密、高性能的零件，但是它无法避免孔洞、空隙等缺陷的出现，且存在力学性能差异和需要后处理加工等问题。为了解决这些问题，需揭示SLM制造工艺参数对性能的影响规律。综述了SLM-316L制备全流程前、中和后期在原始粉末、工艺参数及后处理方面的研究现状，首先讨论了粉末质量指标及制粉工艺对不锈钢制件的影响机理;其次总结了激光输入功率、扫描速度等工艺参数对制件性能影响的研究现状;最后对表面机械磨损处理、电解抛光等后处理方式及制件性能影响规律做了简要总结。阐明了通过SLM影响因素预测不锈钢成形零件力学性能的学术观点，以期为获取高质量零件、促进不锈钢材料的实际应用提供一些参考。

Research Status and Progress of Key Problems in the Whole Process of Selective Laser Melting of Stainless Steel

Selective laser melting (SLM) is the most accurate metal additive manufacturing process for manufacturing metal parts with complex geometric shapes. 316L stainless steel has a face-centered cubic structure, which usually does not undergo a solid phase transition when cooling from the molten state to room temperature. Based on this property, 316L stainless steel has become the most widely used metal material in SLM. Compared with the traditional process, although this process can produce high-density and high-performance parts, it can not avoid the appearance of holes, voids and other defects, as well as mechanical properties differences and the need for post-processing. In order to solve these problems, it is necessary to reveal the effect law of SLM manufacturing parameters on the performance. The research status of raw powder, process parameters and post-processing of SLM-316L before and during the preparation process was reviewed. The effect mechanism of powder quality index and powder process on stainless steel parts was discussed. Secondly, the research status of the effect of laser input power, scanning speed and other process parameters on the performance of the parts was summarized. Finally, the effects of mechanical wear treatment, electrolytic polishing and other post-processing methods on the performance of the parts were briefly summarized. The academic point of view of predicting the mechanical properties of stainless steel forming parts by SLM affecting factors is expounded, which provides some references for obtaining high quality parts and promoting the practical application of stainless steel materials.