Study on carbide cutting tool life using various cutting speeds for α-β Ti-alloy machining

Current experimental studies have yielded that cutting speed, using carbide cutters, has no significant influence on surface roughness obtained for machining the α-β Titanium alloy Ti-6Al-4V. This paper presents results of experimental investigations carried out on the widely used titanium alloy Ti-6Al-4V using variable cutting speeds as well as different cutting tools at a constant feed rate and depth of cut. The effects of varying cutting speeds on the tool life have been analysed by inspecting the surface roughness of the machined samples and the tool wear observed during machining. As the cutting speed increases, the tool life drops off very rapidly and at higher cutting speed the chips start to ignite because of high heat generation at the cutting zone which is mainly caused by the low thermal conductivity of titanium alloys as postulated. Consequently higher cutting speeds may be used to dramatically reduce the production costs, but the currently available cutting tools will have a very poor tool life. According to this study, it has been identified that the uncoated carbide tool life is comparatively better than that of coated ones at lower cutting speeds whereas the coated ones are preferable at higher cutting speeds. It is expected that the metal manufacturing industries will be highly benefitted by this outcome in selecting the appropriate cutting tool as well as cutting speed according to their desired surface finish and tool life.