Interplay of capillary and elastic driving forces during microstructural evolution: Applications of a digital image model

A recently developed model of curvature-driven, two-dimensional microstructure evolution is modified to include elastic strain energy at solid-fluid interfaces as an additional driving force for mass transport. Local phase distributions within a digital image of the microstructure are used to interpolate an isopotential contour that represents the equivalent sharp surface, along which local properties such as curvature are calculated. To determine the strain energy distribution, a finite element method is employed, using the pixel grid as the mesh. Interface-reaction-controlled mass transport is simulated using a finite difference approach along the interface. Calculations of the strain energy density and chemical potential distributions within simple systems show reasonable agreement with analytical results, and the predicted stability and evolution of such systems also agree with the predictions of other investigators. The model is also applied to a more complex system for which neither analytical nor other numerical methods can be readily used, and useful quantitative information is obtained on the energetics and structural changes.