Face milling of Titanium Alloy Ti-6246 using PVD-TiN coated carbide tools

Abstract

The increasing trend of using titanium alloys in aerospace, chemical, biomedical and petroleum industries are mainly due to their attractive properties such as strength to weight ratio, low density, superior corrosion resistance and compatibility with composite materials (Boyer, 1998 and Brewer et. al., 1998). On the other hand, many researchers have classified titanium and its alloys as “difficult to cut materials” with respect to machinability due to their high temperature strength, low thermal conductivity, low modulus of elasticity and chemical reactivity (Hong et. al., 1993). The inhomogeneous deformation by catastrophic shear during machining tends to fluctuate the cutting force and with its low modulus of elasticity, thereby aggravating tool wear and chatter (Machado and Wallbank, 1990). Great advancement in the development of cutting tools for the past few decades showed little improvement on the machinability of titanium alloys. Previous studies have shown that almost every cutting tool developed so far, including diamond, ceramics and cubic boron nitride, are highly chemical reactive with titanium alloys, causing rapid tool wear and premature tool failure