Effect of nose radius on the chip morphology, cutting force and tool wear during dry turning of Inconel 718

The machinability studies for the Inconel 718 alloy with the coated cemented carbide cutting tool having 0.4 and 1.2 mm nose radius, varying cutting speeds (65, 81, 95 and 106 m/min) with a constant feed rate of (0.15 mm/rev) and a depth of cut (0.2 mm) were conducted. The cutting force decreases with the increase in cutting speed due to the thermal softening of the work surface at a high temperature. With the increase in nose radius a decrease in the cutting force is observed due to the increase in the cutting edge of the tool. The formation of residual stress has a profound effect on the change in the tool morphology during the machining of the alloy. Furthermore, the chip analysis in terms of chip morphology is carried out in detail. The detailed tool fracture studies are conducted and are explained for the various machining processes.