Tool wear characterization in high-speed milling of titanium metal matrix composites

Titanium metal matrix composites (Ti-MMCs) have been successfully incorporated into a vast number of products within various industrial sectors. Despite excellent mechanical and physical features, due to the presence of hard and abrasive ceramic particles in metal matrices of Ti-MMCs, various issues have been emerged regarding machining and machinability of Ti-MMCs. Among critical machinability attributes, tool/insert wear and surface quality, in principle average surface roughness, R-a, are the principal critical attributes. This study plans to present an experimental analysis of wear characterization of polycrystalline diamond (PCD) and carbide inserts during high-speed milling of Ti-MMCs. The main wear modes observed were adhesion, abrasion, and diffusion. Oxidation was also observed at under those cutting conditions with elevated temperature. Regardless of the insert used, edge chipping was also observed in milling tests under various levels of cutting. It was observed that cutting speed and depth of cut are the major cutting parameters affecting wear rate in carbide X500 and PCD inserts. Meanwhile, surface roughness R-a was not affected by the cutting parameters used when using PCD insert. Promising tool wear rates also were recorded under low levels of cutting speed and high levels of feed rate when using carbide insert X500.