FOAM-LIKE EVOLUTION IN POLYCRYSTALLINE SYSTEMS FOLLOWING SUCCESSIVE MELT AND GROWTH CYCLES

A stochastic model of multigrain growth which allows for successive me lting-growth cycles is investigated on a square lattice. Two fundament al constraints are introduced: (i) the melted mass amplitude and (ii) the number of cycles guide the process. The evolution of the microstru cture is found to be quite similar to foam systems, i.e. topological r earrangements are observed together with the increase of the-mean grai n area. A drastic crossover between two types of growth regimes is fou nd as a function of the amplitude of the melting-growth cycles. This a llows one to envisage the existence of optimal conditions for polycrys tal processing.