Effect of chromium addition on microstructure and creep strength of as-cast Ti–48Al alloy

The microstructure and creep behaviour of as-cast gamma titanium aluminide based alloys with nominal composition of Ti–48Al, Ti–48Al–2Cr and Ti–48Al–4Cr (at.%) were investigated. Constant load tensile creep tests were performed at temperature and stress of 800 °C and 150 MPa, respectively. Creep characteristics such as steady-state creep rate, time to 1% creep deformation, creep deformed microstructures and creep fracture was analysed. The effect of Cr addition on creep strength were analysed with respect to solid solution strengthening by Cr in γ phase, formation of β phase and comparison with the base binary Ti–48Al alloy.