The performance of ceramic tool materials for the machining of cast iron

Ceramic tools produced by Kennametal Inc. have been used for the machining of three grades of cast iron. The results show that tools based on mixed ceramics give better performance than those based on oxide and nitride ceramics. Study of the tool life and failure modes shows that tool life was determined by the flank face wear, fracture and surface roughness generated on the workpiece. Detailed microstudy of the used tools showed attrition and diffusion to be the dominant wear mechanisms. Attrition was dominant at slower speeds. A diffusion wear mechanism controlled the tool life at higher speeds where spinel formation was observed.