Accurate simulations of cyclic viscoplastic deformation behaviors of single crystal superalloys which are widely used for the manufacture of gas turbine blades are important for the effective design and safety assessment in practice. In this context, based on the in-phase thermomechanical fatigue (IP TMF) and out-of-phase thermomechanical fatigue (OP TMF) experiments of the nickel-based single crystal superalloy with [001] orientation, a modified constitutive model has been developed to describe the deformation behavior under thermomechanical loadings. The TMF experiment results indicate that stable hysteresis
loops with remarkable ratcheting appear in both IP TMF and OP TMF. And it’s worth noticing that the ratcheting growth direction of IP TMF and OP TMF are opposite. By introducing a Schmid stress rate related term to the back stress evolution equation, the slip-based Walker’s constitutive model is modified in this study. And the simulation results of the deformation behavior reveal good agreement with the experiments under different IP TMF and OP TMF conditions.
Deformation behavior during thermo-mechanical fatigue of a nickel-based single crystal superalloy
