High temperature creep behavior and mechanism of a TiAl-based intermetallic

Abstract

The creep mechanism and behavior of a lower plastic lamellar structure TiAl-based intermetallic at 760 °C were investigated. The research results show that the alloy has distinct creep behavior, such as the stages of creep being not obvious and the creep behavior being sensitive to stress. There is a stress critical value, about 200 MPa in experimental alloy. While the stress is lower than the critical value, there is the secondary stage after the primary stage in creep curves, and with the increase of the stress, primary creep stage becomes short and directly follows the tertiary creep stage in the creep curves. When the stress is over the critical level, there is a shorter steady-state creep stage in the curve of strain rate in intermetallic, then strain rate increases rapidly. The deformation mechanism at 760 °C is main due to the slip of dislocation.