Directional solidification and creep deformation of a Ti–46Al–1.5Mo–0.2C (at.%) alloy

Tensile creep properties of a directionally solidified Ti–46Al–1.5Mo–0.2C (at.%) alloy were investigated. By directional solidification, fully lamellar PST-like crystals were produced. Specimens of varying lamellar orientations were crept at stresses from 120 to 240 MPa at 750 and 800 °C for more than 500 h. Specimens with the lamellar boundaries parallel to loading axis are shown to have excellent creep properties. However, there is a significant loss in creep strength as the degree of misalignment between lamellar orientation and loading axis increases. The change in the creep behavior with lamellar orientation could be correlated with the change in yield strength as a function of lamellar orientation.