PCBN刀具干湿切削加工淬硬钢时的磨损对比

Comparison of wear during dry and wet cutting of quenched steel with PCBN cutting tool

本文研究了在一定切削参数下干、湿式切削加工淬硬钢时四种PCBN刀具的刀具寿命、磨损形式和磨损机理。通过扫描电子显微镜观察不同切削行程下刀尖形貌和刀具后刀面磨损量,并对刀具前后刀面进行能谱分析。结果表明湿式切削时的后刀面磨损量小于干式切削,说明刀具湿切比干切时具有较好的性能;PCBN刀具的磨损形式有前刀面磨损、后刀面磨损,其中前刀面磨损的表现形式为月牙洼磨损,磨损机理为机械磨损、氧化磨损和黏结剂磨损,而后刀面磨损机理有机械磨损、氧化磨损、黏结剂磨损和扩散磨损等;同时还发现CBN含量下降,刀具的后刀面磨损量也有下降趋势,即刀具的切削寿命有延长趋势。

The lifespan, wear form and wear mechanism of four kinds of PCBN cutting tools were studied through dry cutting and wet cutting of quenched steel （45 CrNiMov） under given cutting parameters. The morphology and flank wear of PCBN tip in different cutting stroke were observed via SEM and analyzed by EDS. The results show that the wear of flank face in wet cutting is less serious than the case in dry cutting, which means that the cutting tools have better performance when used in wet cutting. The wear forms of PCBN cutting tools include rake wear and flank wear. The rake wear is presented as crater wear and its wear mechanisms are abrasive, oxidation and adhesion, while the wear mechanisms of flank wear are abrasive, oxidation, adhesion and diffusion. And also, we know that the wear amount of rear face decreases, i. e. , the lifespan of cutting tools become longer with lower CBN content.