Phase-Field Simulation on Coarsening of the γ' Phase Particles in Ni-Based Superalloys Considering Elastic Inhomogeneity

摘要

A phase-field simulation is performed to examine the effect of elastic inhomogeneity between the γ and γ' phases on coarsening of the γ' phase in Ni-based superalloys. In the calculation of elastic strain energy, the mechanical equilibrium equation in elastically inhomogeneous system is solved by an iterative-perturbation scheme. On the basis of the elastic constants of a practical Ni-based superalloy, a series of simulations is performed in which both elastic anisotropy and shear modulus are varied independently. The variation of elastic anisotropy gives significant effect on both morphology and size distribution function of the γ' particles, whereas the variation of shear modulus gives little effect on them. Furthermore, it is found that the coarsening rate constant of the cubic growth raw changes and increases with increasing the standard deviation of the γ' size distribution.