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

Abstract

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.