CURRENT STATUS OF GRAIN GROWTH MODELLING WITH SPECIAL REFERENCE TO NANOCRYSTALLINE MATERIALS

摘要

Current situations in the modeling of grain growth are critically reviewed. The models of Hillert, Lucke et al, and Mullins are reviewed briefly and shown to be inadequate in describing one or more features of grain growth phenomenon. It is well known that models of Hillert and Lucke and co-workers do not give the correct description of the grain size distribution. Mullins' model, although it gives a correct distribution, still fails because it cannot even, in principle, explain the well known fact that the scaled distribution, obtained after the initial growth, is independent of the initial distribution. An approach based on the stochastic methods leads to a more realistic model. The application of these results, to the growth of nanocrystalline materials, is considered. Here it is shown, that the mobility of the triple junctions may play a significant role.