Influence of cutting speed and particulate content on polycrystalline diamond tool wear in machining AA7075/TiB₂ in situ aluminum matrix composites

Aluminum alloy AA7075 was reinforced with in-situ synthesized TiB₂ particles (0–12 wt%) to prepare aluminum matrix composites (AMCs) by casting. The cast composite bars were machined using polycrystalline diamond (PCD) tool inserts. The influence of cutting speed and TiB₂ particle content on the tool wear was quantified. The rake face, flank face, and machined surface morphologies were studied using a field emission scanning electron microscope (FESEM). Energy dispersive X-ray analysis (EDS) was carried out on the rake face across a defined line. The increase in cutting speed and TiB₂ particle content increased the tool wear. The highest cutting conditions accelerated tool wear and caused chipping. The mechanisms responsible for tool wear were identified as adhesion, abrasion, chipping and diffusion. The state of the tool wear was directly reflected on the machined surface in the form of deposited material and feed mark ridges.