车削45%SiCp/Al复合材料刀具寿命及磨损机制研究

为探索金刚石刀具(PCD)和涂层硬质合金刀具加工45%SiCp/Al复合材料时的刀具磨损、切削力、表面粗糙度的变化规律,对45%SiCp/Al复合材料进行了切削试验。分别使用三向测力仪对切削力进行测量,光学显微镜对刀具磨损进行了观察和测量。分析了PCD和涂层硬质合金刀具磨损的演变过程及刀具磨损对切削力、表面粗糙度的影响规律。研究结果表明,对于PCD刀具,前刀面磨损形式依次为晶粒脱落、磨粒磨损、粘结磨损并存在崩刃。后刀面的主要磨损形式为磨粒磨损,并伴有积屑瘤的产生。硬质合金刀具前刀面磨损形式依次为涂层脱落、磨粒磨损,后刀面出现严重磨粒磨损并且出现粘附现象,用PCD刀具切削45%SiCp/Al复合材料,切削力随积屑瘤增长或脱落呈周期性变化。用涂层硬质合金刀具切削时,主切削力是PCD刀具的两倍。对于PCD刀具,表面粗糙度也随积屑瘤呈周期性变化。涂层硬质合金刀具切削45%SiCp/Al复合材料的表面粗糙度大于PCD刀具,并且随切削距离增加急剧增长。

Research on Tool Life and Wear Mechanism During Turning 45%SiCp/Al Composite Material

In order to explore the variation rule of tool wear,cutting force and surface roughness when machining 45%SiCp/Al composites with PCD and coated carbide cutting tools,the cutting test of 45%SiCp/Al composites was carried out.Cutting force was measured by three-way dynamometer and tool wear was observed and measured by optical microscope.The evolution process of PCD and cemented carbide tool wear and the influence of tool wear on cutting force and surface roughness are analyzed.The results show that for PCD tools,the wear forms of rake face are grain shedding,abrasive wear,adhesion wear and tipping.The main form of wear on the flank is abrasive wear and is accompanied by built-up edge.The wear form of the cemented carbide rake face is the coating peeling off and the abrasive wear.Severe abrasive wear and adhesion both occur on the flank.The 45%SiCp/Al composite was cut with a PCD tool,and the cutting force changed periodically as the built-up edge grew or fell off.When cutting with a coated carbide tool,the main cutting force is twice that of a PCD tool.For PCD tools,the surface roughness also varies periodically with the built-up edge.The surface roughness of the coated cemented carbide tool cutting 45%SiCp/Al composite is greater than that of the PCD tool and increases sharply with increasing cutting distance.