Performance and wear mechanism of spark plasma sintered WC-Based ultrafine cemented carbides tools in dry turning of Ti-6Al-4V

Cutting performance and failure mechanisms of spark plasma sintered (SPS) ultrafine cemented carbides in dry turning Ti-6Al-4V were studied. The tools of UYG8 (WC-8wt%Co) and UYG8V2B10 (WC-8wt%Co-0.2 wt%VC-1.0 wt%cBN) exhibited higher lifetime and better processing quality than the commercial YG8 cemented carbide tool. The cutting distance of UYG-8 and UYG8V2B10 tools are 1.8 and 1.6 times longer than that of YG8, respectively. Cuffing-edge breakage was found as the main failure forms of the SPS cemented carbide tools containing low Co content (<= 6 wt%), whereas the SPS cemented carbide tools containing high Co content (>= 8 wt%) exhibited flank and rake wear as main failure forms caused by abrasion, adhesion, diffusion, and oxidation. UYG8V2B10 tool wear mechanism was affected by cutting speed and depth. Wear mechanisms of UYG8V2B10 tool are mainly adhesive wear and oxidative wear at low cutting speed, but follow adhesive wear and diffusive wear at higher cutting speed. Moreover, with increasing cutting depth, tool failure forms are mainly breakage and chipping, largely induced by high cutting temperature and severe cutting vibration.