The asynchrony of orientation rotation at 750 °C/750 MPa creep in a [011]-oriented Ni-based single crystal superalloy

The Ni-based single crystal superalloy in [011] orientation exhibited poor creep properties at intermediate temperatures. Detailed knowledge of the damage mechanism was still not deeply understood. Here, the damage mechanism resulting from the orientation rotation was proposed. The deformation microstructure depended on the distance from the fracture; at the farther position, there were micro-twins, while at the nearer position were stacking faults. Both micro-twins and stacking faults all originated from the activity of a single {111} <112> slip system. The activity of a single {111} <112> slip system would lead to orientation rotation, which was asynchrony due to the sample being laterally constrained. The asynchrony of orientation rotation would cause nonuniform deformation and localized force inhomogeneity, leading to premature failure of the specimen.