Wear characteristics of nano-polycrystalline diamond tool in cutting of tungsten carbide

Abstract

Nano-polycrystalline diamond is a binderless diamond synthesised by the direct conversion of graphite under high pressure and high temperature. This diamond has the same or higher hardness than synthesised monocrystalline diamond and is expected to be an effective material for cutting tools. In this study, the cutting of tungsten carbide was conducted using two monocrystalline diamond tools, a chemical vapour deposition (CVD) diamond tool and a nano-polycrystalline diamond tool to investigate their wear characteristics in terms of the diamond structure and composition. A supply of chemical solution coolant resulted in a stable machined surface, and a negative back rake angle of 30° was shown to provide the minimum tool wear and machined surface roughness. The nano-polycrystalline diamond tool shows excellent wear resistance superior to those of the two monocrystalline diamond tools and CVD diamond tool in continuous cutting as well as better wear resistance than the CVD diamond tool in intermittent cutting.