SiC_p/2024Al复合材料超精密车削刀具磨损机理研究

Single Crystal Diamond Tool Wear Mechanism during Ultra-precision Turning of SiC_p/2024Al Metal Matrix Composites

对超精密车削SiCp/2024Al复合材料时的单晶金刚石(SCD)刀具磨损模式及其机理进行了研究。结果表明,刀具交替切削硬质SiC颗粒和铝合金基体而产生的交变应力以及SiC增强颗粒对切削刃的高频冲击作用是促使SCD刀具发生崩刃和剥落的主要原因。切削时的高温高压及增强颗粒的微切削作用致使刀具产生明显的磨粒磨损。试件切削表面的XRD物相分析及刀具后刀面的拉曼物相分析表明,SiC增强颗粒的磨粒磨损与铝合金基体中铜元素催化作用的共同作用是SCD刀具后刀面在较低温度下发生严重化学磨损的内在机制。

The wear pattern and its mechanism of single crystal diamond（SCD） tools were investigated during ultra-precision turning of SiC particle--reinforced 2024 aluminum matrix composite. The results show that the stress alternates due to the tool cutting the soft aluminum alloy matrix and the hard reinforcement particle alternately, and the high frequency impact of the SiC particles on the tool edge causes the chipping and peeling. The high temperature and pressure, and the micro cutting effect of the reinforcement results in the abrasive wear of SCD tools. The results of XRD（X--ray diffraction） analysis on the machined surface and Raman analysis on the flank face show that the combined effect of abrasive wear of SiC particles and catalysis of copper in the aluminum matrix leads to the sever graphitization of diamond tools.