The grain refining effect of energy competition and the amorphous phase in nanocomposite materials

The effect of refining a two-phase nanocrystalline–amorphous (NC–a) nanocomposite microstructure was examined by performing Monte Carlo simulations. The results showed that the ratio of NC–NC grain boundary energy (Jgb) and NC–a interfacial energy (Jint) determines the two-phase microstructure and controls its stability. The optimal stable microstructure was found with Jgb/Jint = 10 and amorphous fraction f = 0.15, where almost all the grains are surrounded by the thinner amorphous phase and the grain size distribution obeys the log-normal form very well.