Tear-off wear mechanism of sintered diamond tool in cutting SiC-particle-strengthened epoxy composites

Abstract

This study concerns the wear of sintered diamond tools in the cutting of SiC-particle–epoxy composites. The effects of the SiC particle size, volume ratio in the composite and diamond grain size of the cutting tool on tool wear were investigated. The experimental work has shown that a coarse-grained diamond tool exhibits higher wear resistance than a corresponding fine-grained tool. Greater tool wear was obtained in cutting the composites that had coarser particles and a higher volume ratio of SiC. Moreover, it was found that the tool wear increases drastically when the SiC particles are larger than the tool grains. A wear model of the tool was proposed, in which the tool is worn mainly by the `tear-off' mechanism of the diamond grains. This model could explain the experimental results by comparing the pushing force of an SiC particle with the tear-off resistance of the diamond grains of the tool. Finally, a fatigue-like empirical curve was established. This curve can be used to predict the wear of the tool during cutting of the composite.