The effect of tool edge preparation on tool life and workpiece surface integrity

Titanium alloys are classified as ‘hard to machine’ due to their intrinsic properties of low thermal conductivity, low modulus of elasticity, high strength at elevated temperatures and high chemical affinity with all available cutting tool materials. The α-β alloy Ti-6Al-4V is the most common alloy and is used extensively in the aerospace industry for structural components and as compressor blades, discs, casings, etc., in the cooler parts of gas turbine engines. It is critical to industries such as the aerospace industry that the effects of operating parameters on surface integrity are known and understood before new tool geometries and strategies are accepted. There is extensive literature available detailing all aspects of the machinability of titanium alloys, which is briefly reviewed; however, little of this referes specifically to surface integrity. This paper focuses on the effects of cutting tool preparation, cutting speed and feed rate on tool wear/life with special emphasis on workpiece surface integrity.