Motion of crystalline inclusions by interface diffusion in the proximity of free surfaces

Triggered by experimental observations of nanometer-sized Ni precipitate motion in a La2O3 matrix, the migration and morphological evolution by interface diffusion of an initially circular two-dimensional precipitate located near the free surface of its matrix is numerically investigated by means of phase-field simulations. Considering isotropic interface and elastic energies, it is found that the precipitate migrates towards the free surface, suitably adapting its shape during the motion. The case of two precipitates located near the free surface is also considered as well as the problem of an evolving precipitate near a squared corner of the matrix free surfaces. [Figure not available: see fulltext.].