The Machining of Gamma-TiAl Intermetallic Alloys

Published in the Annals of the CIRP, Vol. 54/2/2005. Titanium intermetallic materials are likely to play a significant role in the production of future aeroengines. The paper details the machinabilty of a range of gamma titanium aluminide (gamma-TiAl) intermetallic alloys when turning, grinding, HSM, drilling, EDM and ECM. Comprehensive literature review data are augmented with experimental results for turning, turn-milling and temperature measurement when high-speed milling. Despite the ability to produce crack-free surfaces when grinding and HSM, turning and drilling remain problematic. Turned surfaces are in general characterised by workpiece smearing, numerous arc-shaped cracks, subsurface lamellae deformation and significant strain hardening, although the use of PCD tooling and ultrasonic assisted cutting has been shown to minimize these effects. Authors: D.K. Aspinwall, R.C. Dewes (University of Birmingham), A.L. Mantle (Rolls-Royce plc).