干切钛合金Ti-6Al-4V时硬质合金刀具磨损行为研究

Research on wear behavior of cemented carbide tool in dry machining Ti-6Al-4V

针对航空发动机典型零件钛合金膜盘在加工过程中刀具磨损严重、加工效率低的问题,采用硬质合金刀具进行钛合金外圆车削加工试验研究,利用带有能谱分析的扫描电镜观测,结合刀-屑接触面摩擦状态,分析刀具磨损形貌与刀具磨损机理;重点分析了刀具材料流失的具体过程,并给出了刀具材料从基体脱落的物理演变过程模型。结果表明:在切削过程中刀-屑接触面伴随着严重的粘结、扩散以及氧化现象,随着切削速度的提高,加速了这种现象的发生;所建立的演变模型能够很好地反映刀具材料的流失过程。

In machining titanium alloys membrane disc which is the typical aircraft engine part, tool wear is serious and processing efficiency is very low. In order to solve these problems, the cemented carbide tool （WC - Co） is used for the experiments of dry cylindrical turning titanium alloy Ti -6A1 -4V. A scanning e- lectron microscopy （SEM） equipped with energy dispersive X -ray spectrometer （EDS） is used to ob- serve tool wear morphology. Based on analyzing the friction characteristic at tool - chip interface, tool wear mechanism is also studied and the loss process of cutting tool material is analyzed. A physical evo- lution model which reflects the falling off of tool material from tool substrate is established. The results show that there exists serious adhesion, diffusion and oxidation at tool -chip interface and increasing cutting speeds accelerate their occurrence. The physical evolution of tool wear behavior can reflect the loss process of tool material very well.