Wear of Polycrystalline Diamond Tool in Cutting of SiC Grain Reinforced Plastic. Influence of Grain Sizes of SiC and Diamond.

Abstract

The wear of a polycrystalline diamond tool in the cutting of a SiC grain-reinforced plastic composite is investigated. The effects of grain sizes of SiC in the composite and the diamond of the tool were concerned. The cutting experiments showed that higher wear of the tool occurs in cutting of the composite with larger SiC grains; the coarse-grained tool exhibits a higher wear resistance than the corresponding fine-grained one for all composites. Moreover, tool wear is increased drastically when the SiC grains are larger than the tool grains. On the other hand, a wear called the tear-off model, was proposed to explain the wear mechanism of polycrystalline diamond tools in cutting the SiC-plastic composite. The model illustrated that the greater wear of the tool with the larger SiC grains call be attributed to the iscrease in debonding force of a SiC grain. Finally, an empirical relation, introduced as a fatigue-like curve, between the maximum stress on the tool grains and the number of stress cycles was established to describe the generalized relationship between the SiC grain size in the composite and the flank wear of the tool, taking into consideration the SiC volume ratio, SiC size and tool grain size.