Damage Propagation of Ceramic Cutting Tools

Ceramic tool and CBN tool have usually been used to machine many kinds of advanced materials with their superior properties such as heat-resistance, high hardness and strength and wear-resistance. In this paper, two kinds of commercially available ceramic tips of Alumina group and Silicon-nitride group are selected and their friction abd fracture properties are investigated for the cuttings of cast iron FC25 and high hard steel alloy SKS93. The wear propagation phenomena of the cutting tool edges are microscopically observed and investigated in detail under both the normal (continuous) and the discontinuous cutting condition. Through this research, the relations between brittleness of the tool material and the feature of cutting force induced are made clear