Application of a modified Ostwald ripening theory in coarsening of γ′ phases in Ni based single crystal superalloys

A modified Ostwald ripening theory was used to evaluate the coarsening behavior of γ′ phases in Ni based single crystal superalloys during thermal exposure. After introducing a dimensionless factor correlated with volume fraction of γ′ phase into the classical Lifshitz-Slyozov-Wagner (LSW) coarsening theory, this model was thus developed by coupling formulaic interfacial energy and diffusion coefficient (including activation energy and pre-exponential factor) as function of alloy composition. The coarsening rate coefficients and radius sizes of γ′ phases were then presented, which show good agreement with the corresponding experimental results.