Fabrication and cutting performance of Ti(C,N)-based cermet tools used for machining of high-strength steels

Two kinds of Ti(C,N)-based cermet tools, namely TMWNC and TMWC, were fabricated for the machining of high-strength steels. This research investigated the cutting performances of both tools in terms of chip morphology, cutting force, cutting temperature, and tool wear and failure mechanisms. The results reveal that at the same cutting speed, the life of TMWC tool is longer than that of TMWNC tool with lower cutting force and higher cutting temperature than those of TMWNC tool. For TMWNC tool, at a lower cutting speed of 150 m/min, the tool failure is caused by abrasive wear. And when the cutting speed increases further, the surface flaking and nose breakage occur due to the comprehensive effects of adhesive wear, abrasive wear and thermal mechanical fatigue. While for TMWC tool, the tool wear is severe with chipping, as a result of adhesive wear and abrasive wear. The research has proven the application feasibility of TMWNC and TMWC tools in the machining of high-strength steels. The TMWNC tool with higher fracture toughness presents better edge chipping resistance, and the TMWC tool with higher hardness and hot hardness exhibits better resistance against breakage.