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 micros tructure evolution is modified to include elastic strain energy at sol id-fluid interfaces as an additional driving force for mass transport. Local phase distributions within a digital image of the microstructur e are used to interpolate an isopotential contour that represents the equivalent sharp surface, along which local properties such as curvatu re are calculated. To determine the strain energy distribution, a fini te element method is employed, using the pixel grid as the mesh. Inter face-reaction-controlled mass transport is simulated using a finite di fference approach along the interface. Calculations of the strain ener gy density and chemical potential distributions within simple systems show reasonable agreement with analytical results, and the predicted s tability and evolution of such systems also agree with the predictions of other investigators. The model is also applied to a more complex s ystem for which neither analytical nor other numerical methods can be readily used, and useful quantitative information is obtained on the e nergetics and structural changes. (C) 1998 American Institute of Physi cs.