Rafting of Ni‐Based Superalloys Under Multiaxial Load as Understood by Phase‐Field Simulations and Critical Experiments

Phase‐field simulations coupled with dislocation density‐based crystal plasticity modeling, supported by high‐temperature creep experiments, are employed to investigate rafting behavior in single‐crystal Ni‐based superalloys under uniaxial and shear loading conditions. The model captures both macroscopic creep strain and local microstructural evolution, including dislocation activity, stress distribution, and morphology. Distinct rafting morphologies develop under different loading modes: perpendicular plates under 100 tension, L‐type rafts under 110 tension, and 45°‐aligned plates under shear, aligned with experimental results and demonstrating the model's predictive capability. volume fraction remains stable under shear in the simulation, consistent with the zero stress triaxiality under this loading condition. This framework enables microstructure‐based analysis of performance degradation in high‐temperature components under diverse loading conditions.