Phase‐Field Study of Anisotropic γ′‐Coarsening Kinetics in Ni‐Base Superalloys with Varying Re and Ru Contents

The coarsening kinetics of γ′‐precipitates in single crystalline Ni‐based superalloys is studied using phase‐field simulations. At first, we discuss interdiffusion‐limited γ′‐coarsening in technologically relevant superalloys with the explicit inclusion of up to nine chemical components. The simulations show that an additional influence from the coherency strain leads to a substantially faster coarsening‐evolution compared to the predictions from the LSW‐theory. Second, we perform a virtual experiment to determine the influence of varying rhenium (Re) and ruthenium (Ru) additions on the temporal evolution of the γ‐γ′ microstructure under thermo‐mechanical loads. We observe that a change in the Re content strongly alters the coarsening kinetics. On the contrary, it is found that Ru variations have no significant effect on the coarsening kinetics.