Wear mechanisms that dominate tool-life in machining

The broad concern of the research described in this paper is to identify which of a number of possible tool wear mechanisms have the dominant influence on tool performance for a given toolwork combination. It is proposed that the commercially relevant measure of tool performance is the volume of material worn away from the noseradius region of the tool. A general equation is presented stating that this is affected by adhesion, abrasion, oxidation/adhesion wear, diffusion and plastic deformation of the edge. Micrographs are presented showing these main forms of wear, and the cutting conditions at which they dominate are discussed. The magnitude of the normal stress acting on the cutting edge and the elevated temperature compressive strength of the tool material are shown to limit the maximum rate of metal removal for a particular toolwork combination.