Study of Chip Morphology, Flank Wear on Different Machinability Conditions of Titanium Alloy (Ti-6Al-4V) Using Response Surface Methodology Approach

Introduction

Titanium alloy is one of the most important materials used in the field of aerospace engineering, automobile and marine sector. Most of the components like engines, turbine blades and airframes are made from titanium alloys. The strength to weight ratio and ability to withstand extremely high temperatures are vital criteria for fabrication of such components. The properties of the titanium alloy have the capability to endure in extreme high temperature. Titanium alloy is double as sturdy as aluminum alloys, on the other hand greatly lighter than steel. Due to its low thermal conductivity, it is difficult to machine (Machado and Wallbank, 1990; Ramesh et al., 2008; Ramesh et al., 2008). Titanium alloy is also highly reactive towards chemicals. It has the affinity to weld with the cutting inserts. The chips coming out during machining will stick to the machined surface. It leads to the premature failure of the cutting inserts, formation of chipping and deteriorates the surface finish of the machined surface of workpiece (Ezugwu and Wang, 1997; Neseli et al., 2011). During machining of titanium alloys most of the chips formed are of serrated type. Such types of chips produced throughout the machining operation are due to the decrease in the mechanical strength with an increase in the temperature and also due to the low thermal conductivity of the material (Amin and Talantov, 1986; Mantle and Aspinwall, 1998). So as to enrich the quality of the components, a good surfaces finish of the components with high dimensional accuracy is required. A good surface finish improves the fatigue strength, thermal resistance and corrosion resistance of the product Kramer & Hartung (1980).