选区激光熔化成形金属零件表面粗糙度研究进展

A Review on Surface Roughness of Metals Parts Fabricated by Selective Laser Melting

选区激光熔化(SLM)作为一种新型金属增材制造技术,具有可批量化、高精度、近净成形的特点,尤其适用于制备高性能、复杂精细结构的金属零件,在航空航天和生物医疗等领域具有广泛的应用。然而,目前SLM成形零件的表面质量仍难以直接满足工业应用的需求,优化工艺参数与不同的后处理工艺成为控制成形件表面质量的主要途径。SLM成形件的后处理工艺主要包括机械加工、表面喷砂、激光抛光、化学抛光、电解抛光、超声波表面改性等。但是,具有特定用途的零件对其表面的耐磨性、缺口敏感性、流体摩擦阻力等提出了更高的要求。因此,选择金属零件的后处理工艺时,需要结合零件的应用背景来选择合适的处理工艺。本文基于SLM技术原理和特点,概述了影响SLM成形件表面粗糙度的主要因素,归纳了改善成形件表面粗糙度的主要后处理工艺,最后对控制SLM成形件表面粗糙度所面临的挑战和未来的发展趋势进行了展望及总结。

Selective laser melting(SLM)is a new additive manufacturing(AM)technology,which has the advantage of high efficiency,high precision,near-net forming,and can be used to fabricate high performance components with complex geometries.All of these characters make SLM a wide array of application in aerospace and biomedical fields.However,the surface quality of parts manufactured via SLM still cannot meet the needs of industrial applications.The optimization of process parameters and different post-treatment processes are the main ways to control the surface quality of SLM-fabricated parts.For the post-treatment process of SLM-manufactured parts,it mainly includes conventional machining,surface blasting,laser polishing,chemical polishing,electrolytic polishing,ultrasonic surface modification,etc.Especially for those parts with specific applications,higher requirements are placed on the surface wear resistance,notch sensitivity,and fluid friction resistance.Therefore,it is necessary to select an appropriate posttreatment process based on the characteristics of the SLM-fabricated parts.Based on the principle of the SLM technology,this paper summarizes the main factors affecting the surface roughness and the main post-treatment processes to improve the surface quality of the SLM-manufactured parts.Finally,the challenges and future development trends of controlling the surface roughness of SLM-manufactured metal parts are prospected and assessed.