Effect of initial grain size on grain coarsening in the presence of an unstable population of pinning particles

Abstract

The effects of initial grain size and initial grain size distribution on subsequent grain coarsening in polyphase microstructures with stable and unstable precipitates are investigated using a mean-field statistical model with an adaptive spatiotemporal mesh. The adaptive mesh enables high-throughput simulation of grain coarsening under different initial conditions. It is shown that the final grain size is influenced not only by the value of the Zener drag pressure, but also by both the width of the grain size distribution and the initial grain size. Rapid initial reductions in Zener drag pressure (regardless of whether the second-phase particles are coarsening or dissolving) generally result in a coarser final grain structure for a given initial grain size distribution.