Cutting performance and wear characteristics of Si₃N₄-SiC_w-HfB₂ ceramic cutting tools in turning of ductile cast iron

This research investigated the cutting performance of three different types of Si3N4-based ceramic tools (Si3N4, Si3N4-SiCw, and Si3N4-SiCw-HfB2) with distinct mechanical properties during turning of ductile cast iron. Si3N4 ceramic tool, characterized by high hardness and low toughness, showed minor micro chipping and the highest average flank wear rate during the initial wear stage, leading to a short cutting life of 1679 m. Si3N4-SiCw ceramic tool, with low hardness and high toughness, exhibited the highest average flank wear rate during the middle and final wear stages, resulting a short cutting life (1602 m). In contrast, the Si3N4-SiCw-HfB2 ceramic tool, featuring high hardness and high toughness, demonstrated the lower average flank wear rate during all the wear stages, leading to a longest cutting life (2636 m). The results indicated that the average flank wear rate during the initial wear stage was mainly influenced by toughness, while during the middle and final wear stages, the average flank wear rate was primarily dependent on hardness.