PCD刀具车削不同颗粒含量SiCp/Al复合材料试验研究

碳化硅铝基复合材料具有优良的导热性、较高的比强度和比刚度,在航空航天领域具有广泛的应用前景。由于此复合材料中含有增强相,导致材料的切削加工性能变差。通过试验分析了不同颗粒体积分数(纳米级5%、微米级25%)SiCp/Al复合材料和切削参数(切削速度、背吃刀量、进给量)对刀具磨损和工件表面质量的影响,并对刀具磨损机理进行了研究。试验结果表明,车削微米级25%SiCp/Al材料时聚晶金刚石PCD(Polycrystalline Diamond)刀具磨损更严重,且工件表面质量更差。随着进给量和背吃刀量的增大,工件表面粗糙度值增大,刀片前刀面磨损严重;随着切削速度的增大,工件表面粗糙度值减小,刀片前刀面磨损量增大。选取本文切削参数进行SiCp/Al复合材料的切削加工时,发现刀具磨粒磨损、微崩刃是PCD刀具后刀面磨损的主要成因,且刀具前刀面也会产生积屑瘤。研究结果可为SiCp/Al复合材料PCD车削工艺的优化提供理论基础。

Experimental Research on PCD Tool Turning SiCp/Al Composites

Silicon carbide aluminum matrix composite,which has excellent thermal conductivity,high specific strength and specific stiffness,will be widely applied in the field of aerospace.However,the reinforced phase in this composite results in poor machined surface quality and severe tool wear.Therefore,the influence of SiCp/Al materials with different particle contents(nanometer-level 5%and micron-level 25%)and cutting parameters(cutting speed,cutting depth and feed rate)on tool wear and machined surface quality were analyzed through experiments.The tool wear mechanism was also analyzed.The experimental results showed that PCD tool wear was more serious and the machined surface quality was worse when turning 25%SiCp/Al composite with micron-level particles.With the increases of feed rate and cutting depth,the machined surface roughness increased,and the rake face was seriously worn.With the increase of cutting speed,the surface roughness of the workpiece decreased,and the wear of rake face increased.Under the cutting parameters used in this research,the tool abrasive wear and blade breakage were the main wear mechanisms for PCD inserts,and built-up edge(BUE)will be generated on rake face of the cutting tool.The experimental results provide a theoretical basis for optimizing the turning process of SiCp/Al composite with PCD tools.