Optimization of process parameters for high speed machining of Ti-6Al-4V using response surface methodology

Abstract

Titanium (Ti) and its alloys are excellent contenders while selecting materials in aviation industry. The aerospace industries around the globe are extensively using high-strength, corrosion- and heat-resistant titanium alloys. However, titanium alloys are very difficult to machine due to poor thermal conductivity which causes excessive heat at tool–workpiece junction, springiness, and material build up along the cutting edge of tool. Currently, high speed machining (HSM) is becoming popular due to high material removal rate (MRR) and greater productivity. The HSM of titanium alloys is not less than a challenge. Under prevailing machining scenario and scope of usage of titanium alloys, the HSM process parameters optimization is the utmost need of the hour. Rare work has been done on HSM of titanium alloys in near past, specially beyond cutting speed of 500 m/min. In this paper, an average surface roughness (Ra) model has been developed for milling of titanium alloy (Ti-6Al-4V) using carbide inserts tooling. A series of experiments have been performed using response surface methodology (RSM) for developing a relationship with Ra (output) and machining parameters, i.e., cutting speed, feed, and depth of cut (input variables). It was observed that surface roughness is mainly influenced by depth of cut while cutting speed and feed rate do not have significant effects.