Wear mechanisms of ceramic cutting tools when machining hardened steel AISI D2 cold work tool steel of 60 HRC

Wear mechanisms of mixed ceramic (AI₂O₃ + TiCN) cutting tool when machining hardened steel AISI D2 cold work tool steel was investigated. The machining test was performed on a CNC lathe using three different speeds, namely 120, 180 and 220 m/min, while feed and depth of cut were held constant at 0.06 mm/rev and 0.4 mm based on feedback and suggestion from the manufacturers. Flank and rake face of the cutting tools was monitored at selected time intervals; furthermore, characterization and morphologies of various wears formed at the surface of tool insets after cutting operation are analyzed in detail with a Scanning Electron Microscope (SEM) observation. It was found that the mixed ceramic cutting tools wear mechanism is subjected to not only abrasion, adhesion but also to chipping, especially when machining at high cutting speed of 220 m/min.