Analysis for Machining of Ti6Al4V Alloy using Coated and Non-Coated Carbide Tools

The fundamental machining techniques were established long back. However, machining operations consume a large amount of money annually worldwide. Advanced engineering materials, such as ceramics, MMC, Titanium (Ti), Inconel and its alloys offer properties like high strength at elevated temperature, chemical and wear resistance. Therefore, these materials are being used in making components for aerospace, defence, nuclear, orthopaedic, and marine applications. However, these alloys are classified as a ‘difficult-to-cut’ due to their poor thermal conductivity, reactivity with tool material, high strength and low modulus of elasticity. Besides various measures to improve machinability of these alloys, the key areas of research focuses on selection of cutting tool material and its geometry, use of various machining environments and selection optimum processing conditions to improve tool life, metal removal rate and decrease cutting forces and surface roughness of the machined component. This paper focuses on machinability of titanium alloys under various machining environments such as – dry, flooded and mist jet cooling. The main objective of the paper is to understand the effect of change in machining environment on various aspects of machining of titanium alloys viz. tool wear, cutting forces, surface roughness and chip morphology. It is evident that the flooded and mist jet environments effectively cool the cutting zone and reduce the cutting forces and tool wear 30 and 40% respectively. On the other hand, flooded lubrication and mist jet cooling improves surface quality 20-30% as compared to dry condition machining. Based on this study, optimum conditions to improve machinability of Ti6Al4V alloys are presented.