金属增材制造格栅零件磨粒流抛光

摘要

增材制造(AM)技术对成型复杂结构零件有显著优势,但以选区激光熔融技术为代表的金属增材制造技术固有的“粉末粘附”、“球化效应”所导致的毛糙表面,使零件难以满足使用要求.采用混合粒径磨料介质对增材制造铝合金格栅外表面及细小内孔进行一体化抛光试验研究.通过分析磨粒流加工过程各阶段的微观形貌和表面轮廓测量结果等来研究材料去除过程中零件表面形貌、材料去除和表面粗糙度变化.试验结果表明,磨粒流加工方法能够有效消除“球化效应”导致的零件表面的金属球团簇聚集现象,并能够对增材制造格栅零件外表面和内孔实现有效的抛光,格栅表面粗糙度从初始的14μm降至1.8μm.%Additive Manufacturing (AM) technology is obviously advantageous in producing parts with complex structures.However,it is difficult for the as-built surfaces of AM parts to meet the quality requirement,as the as-built surfaces are deteriorated by the inherent characteristics of powder adhesion and bailing effect of metal AM technologies,e.g.Selective Laser Melting (SLM).The Abrasive Flow Machining (AFM) is used to polish the outer and inner surfaces of additively manufactured aluminum grille parts,with the abrasive media containing grits of different sizes.The variations of surface topology,material removal and surface roughness of the grille are considered by analyses of measurements of micro-topology and profiles during the AFM process.The experiment results show that clustering of molten metal balls due to the bailing effect can be removed effectively from the grille surface,and the surface roughness is reduced from the initial 14 μm to the final 1.8 μm,with pretty good polishing effect being achieved for the outer and inner surfaces of the grille.