High-cycle fatigue failure behavior of nickel-based single crystal alloys with different deviation angles in a high-temperature environment

The high-cycle fatigue failure behavior of nickel-based single crystal alloys with different deviation angles (deviated [001] orientations of 0°, 10°, and 20°) was assessed in this work. At 980 °C/600 MPa, the fatigue life decreases with increasing deviation angle from the [001] orientation.The dislocation motion is mainly Orowan deformation mechanism, and the fatigue mode is crystallographic fracture. At 980 °C/640 MPa, the fatigue life is the longest when the deviation angle is 0°, and it is the shortest when the deviation angle is 10°. The fatigue failure mode is the crystallographic fracture when the deviation angle is 0° and 20°, and it is the noncrystallographic fracture when the deviation angle is 10°. The dislocation motion is mainly a single dislocation or paired dislocation shearing γ’ phase deformation mechanism.