Determination of the Effect of Aluminium During the Machining of Titanium Alloys

High speed milling (HSM) is an area highlighted by the aerospace industry as a potential area for significant cost saving in titanium component manufacture. All titanium alloys used for aerospace components contain aluminium as an alloy addition. The aim of this study is to determine the effect of aluminium content on the machinability and degree of subsurface damage. This will aid future alloy development when designing for high production and enhanced service properties. A combination of complex HSM, simple compression testing and a novel orthogonal cutting technique, developed in-house, has been applied to Ti - xAl binary alloys (where x = 2, 4, 6 and 8 wt.%). This paper will present interesting findings on the role of aluminium during machining, and further, provide evidence for the fundamental effects of aluminium on deformation mechanisms in titanium alloys at high strain rates.