The Effects of Solute and Vacancy Depletion on the Formation of Precipitation-Free Zone in a Model Binary Alloy Examined by a Monte Carlo Simulation

The effects of vacancy depletion and solute atom depletion on the microstructural evolution of the precipitation-free zone (PFZ) near the grain boundary have been examined by Monte Carlo simulations with Kawasaki dynamics. The solute depletion caused by a precipitation of stable phase at grain boundaries lead to a well-defined PFZ, whose width grew by a t power law. The average size of precipitates near the PFZ boundary did not change significantly from that inside the grain. On the other hand, the vacancy depletion did not give a well-defined PFZ boundary, and the average size of precipitates changed gradually as a function of distance from the boundary.