SiC_p/Al复合材料高速铣削加工表面质量及切屑形成机制

Surface Quanlity and Chip Generation Mechanism of SiC_p/Al Composites during High-Speed Milling

使用聚晶金刚石(PCD)刀具,对碳化硅颗粒增强铝基复合材料(SiCp/Al)进行高速铣削加工,研究了加工表面质量及切屑的形成机制。结果表明:刀具进给波纹、工件材料塑性侧流、刀具-工件相对振动和增强颗粒去除过程留下的孔洞、微裂纹、基体撕裂等是SiCp/Al复合材料高速铣削加工表面的主要形成机制;增大切削速度、使用冷却液、降低增强颗粒体积分数、减小增强颗粒尺寸均有助于提高加工表面质量;切屑形态为不均匀锯齿状,增强颗粒体积分数、热处理状态等对切屑形成有显著影响,绝热剪切、孔洞/微裂纹动态形成和扩展是切屑的主要形成机制。

Polycrystalline diamond tools（PCD） were selected to study surface and chip generation mechanisms during high-speed milling SiC-particle-reinforced aluminum matrix composites（SiCp/Al）.The results show that feed marks,materials swelling and side flow,tool-workpiece relative vibration,pits produced during removing reinforment particles,micro-cracks and matrix tearing were the main generation mechanisms of SiCp/Al composites surface during high-speed milling.The machined surface quality could be improved by increasing cutting speed,using coolant,decreasing volume fraction of reinforcement particles,decreasing reinforcement particles size.The chip took uneven sawtooth-like,reinforcement volume fraction and heat treatment condition of matrix had remarkable effects on chip formation.The mechanism of chip were dynamic formation and expending of adiabatic shear,pits and micro-cracks.