High speed machining of aerospace alloy Ti-6Al-4V

Abstract

Titanium (Ti) alloys due to their unique and excellent combination of strength to weight ratio and their resistance to corrosion is an attractive material in aerospace industries. But Titanium and its alloys are difficult to machine materials because of its low thermal conductivity and high chemical reactivity. Even at conventional cutting speeds, conventional tools which are commercially used to machine Titanium need frequent grinding or change of tools. Thus an attempt has been made in this study to evaluate the performance of CBN inserts in machining Titanium alloy (Ti-6Al-4V) at high cutting speed with high pressure coolant. Cutting force, tool life and surface roughness were measured under various cutting conditions. The results are promising and have shown improvement in tool life and surface finish with low cutting force at high cutting speed, low feed and low depth of cut. It has also been found that the prominent reason for the tool wear is diffusion-dissolution, of Cobalt - the binder element present in CBN tools.