Comparative wear behavior of ceramic and carbide tools during high speed machining of steel

Two types of oxide-based ceramic cutting tools have been developed for high speed machining of hardened steel. These tools were made of alumina (Al2O3) and zirconia toughened alumina (ZTA). Commercially available tungsten carbide (WC)-based tools were also used during machining for comparison. In general, ceramic tools exhibited superior performance as compared to the WC tools, especially at higher machining speeds, both in terms of tool life and surface finish of the work-piece. The worn-out tools were observed under a stereo-microscope for studying the role of different wear mechanisms on the tool life. While severe crater wear was observed in the WC tools, only a small amount of edge chipping and nose wear occurred in the ceramic tools during high speed machining. The correlation between the mechanical properties of the tool material, the tool lives and their wear behavior was also studied.