A three-dimensional Monte Carlo model for coarsening kinetics of the bi-continuous system via surface diffusion and its application to nanoporous gold

The coarsening of the two-phase, bi-continuous microstructure via surface diffusion is simulated using a three-dimensional Monte Carlo (MC) model. The coarsening exponent obtained from simulations initially decreases and then saturates at similar to 4 as the temperature increases. Kinetic analysis on nanoporous gold (np-Au) samples, annealed at 450 and 600 degrees C, confirms the prediction of the model. The coarsening probability ratio of np-Au between two annealing temperatures, calculated from the reported activation energy for coarsening of np-Au, is comparable to that of the model, signifying that the simulation successfully mimics the kinetic evolution of the thermally coarsened np-Au via surface diffusion. (C) 2019 Published by Elsevier Ltd on behalf of Acta Materialia Inc.