Microstructural Evolution of Two-Phase Microstructure via a Spin-Exchange-Path-Dependent Rate-Controlled Monte Carlo Simulation Model

Abstract

We investigate the coarsening kinetics and morphological evolution of binary microstructures during phase separation using a spinexchange-path-dependent rate-controlled Monte Carlo (MC) model. A conventional spin-flip Ising model and spin-exchange Kawasaki dynamics have been used to predict the evolution of the microstructures via the diffusion-controlled mechanism. Here, we suggest a new MC model where the control of the diffusion rate is achieved considering the configurational changes as a consequence of the spinexchange. To verify the proposed model, the microstructural characterization using the simulation snapshot patterns, the pair correlation function and the structural factor, is performed to measure the characteristic length and its temporal evolution. From the resultant temporal evolution of the characteristic length, it is found that the dynamics of the system with zero bulk diffusivity achieves a higher value of kinetic exponent of 4 ~ 5 than the conventional Kawasaki dynamics model over the intermediate temperature range. Also, we found that the evolution of microstructure is strongly affected by the volume fraction of the system. Lastly, we compare the results from the proposed model to the coarsening of porous metal system.