Integrated phase field-crystal plasticity framework for simulating heat treatment and deformation of single crystal Ni-based superalloys

Abstract This study presents an integrated phase field-crystal plasticity modeling framework for predicting the microstructure evolution during aging heat treatment and the subsequent mechanical properties for single crystal Ni-based superalloys. The phase field model, based on the Kim–Kim–Suzuki model, accounts for the anisotropic growth and coarsening of precipitates during aging. Specifically, the interfacial anisotropy in the phase field model is used to simulate the morphological evolution of precipitates from an initial spherical/circular shape to a cuboidal/square shape, which is a characteristic feature of the γ ′ precipitate growth in superalloys. Application of the model has been demonstrated in the form of three different case studies. The first case study simulates the two stage aging of a commercial single crystal superalloy, CMSX-4, followed by prediction of the temperature-dependent tension–compression asymmetry of the aged microstructures. These results highlight the capability of the model to predict processing-microstructure-mechanical property correlations. The second case study simulates the microstructure evolution during long-term aging of CMSX-4 for relatively larger microstructures, highlighting the capability of the model to predict precipitate coarsening. Further, the effect of varying the cooling rate on the microstructure evolution is also demonstrated. The third case study simulates the microstructure evolution during aging at relatively lower temperatures for Ni–Al alloys with different compositions. These results highlight the capability of the model to predict the change in precipitate morphology from circular to square shape during the initial stages of aging. Model predictions of the precipitate size, volume fraction and mechanical properties have been compared with relevant literature data. Overall, this integrated phase field-crystal plasticity framework offers a powerful tool for the computational design of single crystal superalloys.