Cyclic crack growth in titanium aluminides

Micromechanisms of fatigue crack growth have been studied in specific Ti3Al-based aluminides and TiAl-based aluminides. Effects of test temperature, environment and microstructure on fatigue crack growth resistance are considered. For both intermetallic systems brittle mechanisms of crack extension are observed at room temperature, and such mechanisms persist in the TiAl-based aluminides considered to a test temperature of 800 °C. The implications of such observations for the engineering application of these materials are addressed briefly.