THE DYNAMICS OF PRECIPITATE EVOLUTION IN ELASTICALLY STRESSED SOLIDS .2. PARTICLE ALIGNMENT

The effects of elastic stress on the spatial distribution and morpholo gy of misfitting particles during coarsening in an elastically anisotr opic system are examined. No assumptions are made on the morphology of the particles; they evolve in a manner consistent with the diffusion and elastic fields in the system. Through these calculations we have i dentified the microstructural signature of elastic-stress induced part icle migration. In addition, we find that elastic stress leads not onl y to particle alignment along the elastically soft directions of the c rystal, but also prevents particle coalescence. When the particles are aligned along the elastically soft directions of the crystal the morp hology of the particles differs from the equilibrium shape of isolated particles in a manner which depends on the size of the particles. In addition, the elastic-stress induced equilibrium separation between al igned particles decreases with increasing particle size. We show that the effects of elastic stress, due to either applied tractions or othe r particles, on the morphology and spatial distribution of the particl es can be understood in terms of the configurational forces generated by this stress. Configurational force fields generated by misfitting p articles are used to explain the results of our dynamical calculations .