单晶金刚石刀具切削各向同性热解石墨的磨损机理

Wear Mechanism of Single Crystal Diamond Tool during Cutting of Isotropic Pyrolytic Graphite

为了研究各向同性热解石墨切削过程中单晶金刚石刀具磨损及其对加工质量的影响,对各向同性热解石墨材料进行了切削试验。观测了刀具磨损形貌的演变过程,分析了刀具磨损机理以及刀具磨损对加工表面质量的影响。研究结果表明,在切削距离逐渐增加的情况下,单晶金刚石刀具后刀面磨损区域逐渐增大,磨损形貌分为平行沟槽和微细网状两种。切削过程中产生的颗粒状切屑和交变应力分别是导致磨粒磨损和解理磨损的主要原因。切削距离300 m内,试件加工表面粗糙度值Ra在0.2~0.4μm之间波动,切削距离达到1000 m以后,试件加工表面粗糙度值明显增大,但是保持了相对稳定,表面粗糙度值Ra约为0.8μm。

In order to research tool wear and its effect on machining quality during cutting of isotropic pyrolytic graphite, an experiment of turning of isotropic pyrolytic graphite using single crystal diamond tools was conducted. The evolution process of tool wear was observed, both tool wear mechanism and the effect of tool wear on surface machined quality were studied. Research results show that the wear area on tool flank face increases gradually with the increasing of cutting distance. The wear area can be divided into two kinds of morphology： parallel grooves and micro-reticular. Granular chips and alternating stress generated during cutting process were the main reason for abrasive wear and cleavage wear, respectively. When the cutting distance was smaller than 300 m, the specimen machined surface roughness Ra was between 0.2-0.4 μm. When the cutting distance was larger than 1000 m, the specimen machined surface roughness significantly increased but remained stable, the specimen machined surface roughness Ra was about 0.8 μm.