Investigation on the performance of spark plasma sintered ultrafine WC-Co cemented carbide end mills during high-speed precision milling of Ti-6Al-4V alloy

Abstract

In this study, ultrafine WC-Co and WC-(Ti,W)C-Co cemented carbide end mills were fabricated via spark plasma sintering. The performance of those tools in the high-speed precision machining of Ti-6Al-4V alloy was investigated, focusing on the analysis of tool wear mechanisms, cutting performance, and machined surface roughness. The results reveal that adhesive wear emerges as the predominant wear mechanism influencing the performance of both tools. The addition of (Ti,W) C leads to high workpiece element enrichment on the flank face of the tool, increasing subsequently severe adhesive wear. WC-(Ti,W)C-Co displays a greater propensity for crack propagation and material chipping, culminating in premature tool failure with the formation of significant wear craters and cutting edge breakage. Conversely, WC-Co exhibits comparatively milder wear patterns and a reduced incidence of cutting edge chipping due to its inherent resistance to adhesive wear. Additionally, the comparison of the developed ultrafine cemented carbide tools with similar commercial tools demonstrates that WC-Co has superior cutting performance in terms of tool life, 1.5–1.8 times longer than the commercial tools. These findings provide guidance for optimizing machining strategies and developing advanced tool materials for high-speed milling titanium alloy.