Development of novel tool for cutting of carbon-fiber-reinforced plastics (Positive use of abrasive wear at tool edge for reduction in cutting force)

This paper describes a novel design concept for a tool for cutting carbon-fiber-reinforced plastic (CFRP) composites. The cutting tool, which is termed a two-layer tool, was fabricated from two materials with a spatial distribution of hardness around the tool edge. In the two-layer tool, the rake face is made of a material with a relatively high wear resistance, i.e., polycrystalline diamond (PCD), whereas the flank face is made of a material with a relatively low wear resistance, i.e., tungsten carbide (WC-Co). The results of milling tests conducted with a unidirectional CFRP laminate and the two-layer tool showed that the existence of a hardness distribution works to reduce cutting forces, because the wear process of the two-layer tool develops with a constant roundness at the tool edge over relatively long cutting distances. A simplified model was developed to describe how friction force is reduced. Increasing the difference between the wear resistances of the PCD layer and the WC-Co substrate and increasing the clearance angle of the tool edge were found to be effective in reducing the cutting forces. The finding of this study will be helpful in the development of novel design concepts for extending the life of tools for cutting CFRP composites