Effect of elastic interactions on coarsening in elastically inhomogeneous multiphase systems

We investigate the effect of interactions between inclusions on the coarsening behavior of elastically inhomogeneous multiphase systems with lattice misfit using a recently introduced two-dimensional multiscale model based on the classical time-dependent density-functional theory. We show that spontaneous shape changes are very efficient in limiting the impact of the interactions on the chemical potential of inclusions. For this reason, the interactions between isolated pairs of inclusions are unable to significantly affect coarsening. At higher volume fraction, the efficiency of shape changes drops and major shifts of the chemical potential are observed; these are shown to be strong enough to counteract capillarity. For example, we show that sufficient confinement by neighboring inclusions causes inverse coarsening and we provide illustrations of this. We also examine the effect of interface elasticity in the presence of interactions. We demonstrate that elasticity induces kinetic faceting and gives rise to oscillations in the chemical potential of the inclusions. This is shown to lead to the stabilization of microstructures composed of inclusions of various sizes. Finally, we propose a simple modified Lifshitz-Slyozov-Wagner model for assessing the effect of interactions on coarsening. The results are shown to be in excellent agreement with experiment.