The effect of machining on surface integrity of titanium alloy Ti–6% Al–4% V

Abstract

This paper gives the investigation on surface integrity of rough machining of titanium alloy Ti–6% Al–4% V with uncoated carbide cutting tools. The experiments were carried out under dry cutting conditions. The cutting speeds selected in the experiment were 100, 75, 60 and 45 m min −1. The depth of cut was kept constant at 2.0 mm. The feed rates used in the experiment were 0.35 and 0.25 mm rev −1. Two types of insert were used in the experiments. For a range of cutting speeds, feeds, and depths of cut, measurements of surface roughness of machined surface, microhardness and work hardening backed up with scanning electron microscope were taken. The surface of titanium alloy is easily damaged during machining operations due to their poor machinability. The machined surface experienced microstructure alteration and increment in microhardness on the top white layer (≤10 μm) of the machined surface. Severe microstructure alteration was observed when machining with the dull tool. In addition, surface roughness values obtained were within the limit (<6 μm) stipulated by ISO for rough machining.