【摘要】 对PCD/PCBN两种超硬刀具高速切削钛合金TC4形成的锯齿形切屑几何表征进行了对比研究。研究发现：齿距大小取决于靠近刀尖处切削底层材料发生热塑剪切失稳所需切削路程长短，齿距都随切削速度增加而减小，都随进给量和背吃刀量增加而增加。锯齿化程度的大小主要取决于一节锯齿切屑相对于后续锯齿切屑的向外滑移距离，锯齿化程度都随切削速度、进给量、背吃刀量增加而呈现增加趋势。锯齿化频率都随切削速度增加而增加，都随进给量、背吃刀量增加而减小。另外，相同切削用量下，PCBN刀具齿距整体小于PCD刀具，而锯齿化程度及锯齿化频率整体高于PCD刀具。更多还原

【Abstract】 The geometrical characterization of the sawtooth chips formed by high-speed cutting of tita-nium alloy TC4 with superhard cutting tools PCD/PCBN was compared.It is found that the pitch depends on the cutting path length required for the thermoplastic shear instability of the cutting bottom material near the tool tip.The pitch decreases with the increase of the cutting speed, and increases with the increase of the feed rate and the back feed rate.The degree of serration mainly depends on the outward slip distance of a sawtooth chip relative to the subsequent sawtooth chip.The degree of serration increases with the increase of the cutting speed, the feed rate and the back feed rate.The serration frequency increases with the increase of the cutting speed, and decreases with the increase of the feed rate and the back feed rate.In addition, with the same cutting parameters, the tooth pitch of PCBN is smaller than that of PCD,while the serration degree and serration frequency of PCBN are higher than those of PCD.更多还原