Investigation of monolayer coated WC inserts on turning Ti-alloy

A single-layered AlCrN-based coating on the WC inserts was fabricated using the physical vapor deposition technique. Micro-hardness, coating thickness, surface morphology and elemental composition of coating on carbide insert were observed. The turning operations were conducted on Ti-6Al-4V alloy with coated carbide (AlCrN-cc) and without coated carbide (Ucc) inserts under the conventional and cryogenic coolant (LN2) conditions. The 2D roughness value (R-a) and turning forces were measured for an experimental parameter, which comprised of various feed (f), depth of cut (d) and cutting speed (V-c). The tool edge morphology, elemental composition of worn carbide inserts was analyzed. The results showed the development of a lower surface roughness on a machined surface, reduction in cutting forces during machining by AlCrN coated inserts with a cryogenic coolant compared with a conventional coolant. In addition, the cut chips were analyzed and compared for the conventional and cryogenic coolant conditions.