纯铁车削中不同材质刀具磨损的实验研究

Experimental Study on Tool Wear of Different Materials in Pure Iron Turning

采用硬质合金刀具、CBN刀具和陶瓷刀具干车削纯铁,研究了不同材质刀具以80m/min线速度车削纯铁时刀具磨损形貌和机理。结果表明:刀具磨损主要发生在前刀面;硬质合金刀具磨损形式以前刀面月牙洼磨损为主,伴有后刀面边界磨损;CBN刀具和陶瓷刀具前刀面出现月牙洼磨损轮廓,CBN刀具后刀面有边界磨损,陶瓷刀具出现涂层剥落。硬质合金刀具的主要磨损机理为黏结磨损、磨粒磨损和氧化磨损;CBN刀具和陶瓷刀具的主要磨损机理为氧化磨损。CBN刀具伴有轻微磨粒磨损和黏结磨损,陶瓷刀具有轻微黏结磨损。刀-工件之间黏结强度不同将影响刀具的黏结磨损形式和磨损位置。在低速干切削条件下,CBN刀具和陶瓷刀具比硬质合金刀具切削性能更优。

In this work,experiments of pure iron dry turning were conducted by using carbide tools,CBN tools,and ceramic tools.Through cutting pure iron by tools with different materials and cutting speed 80 m/min,the tool wear morphology and mechanism were studied.The results show that tool wear mainly occurs on the rake face.The wear morphology of carbide tools is mainly crater,accompanied by boundary wear on the flank face.Crater contour occurs on the rake face of CBN tools and ceramic tools;boundary wear happens on the rake face of CBN tools;coating peeling off appears on ceramic tools.The main wear mechanisms of carbide tools is adhering wear,abrasive wear and oxidation wear.The main wear mechanism of CBN tools and ceramic tools is oxidation wear.CBN tools showed slight abrasive wear and adhering wear,while ceramic tools were found to have slightly adhering wear.Differences of bond strength between tool and workpiece may affect tool adhering morphology and adhering position.Under low cutting speed and dry cutting conditions,CBN tools and ceramic tools perform better than carbide tools.