Wear and fracture of advanced ceramic tool materials and role of cracks in machining steels

摘要

Wear resistance and fracture resistance of several advanced ceramic tool materials in the continuous and intermittent machining of carbon steels are summarized in the present study, as well as the morphologies of various wear and fracture cracks formed after cutting operation in the tool materials. Forming mechanisms of these cracks and their effects on the wear and fracture resistance of ceramic tool materials are discussed further with SEM analyses. It is reported that the formed cracks will result in the acceleration of the tool wear. The formation and propagation of cracks is closely related with the initial tool fracture. The resulted fatigue cracks and thermal cracks from the co-action of mechanical and thermal stresses is one of the dominant reasons for the failure of ceramic cutting tools.