Accelerated precipitate coarsening due to a concomitant secondary phase transformation

摘要

The effect of a concomitant secondary phase transformation on the coarsening of spherical precipitates inherited from a previous primary phase transformation is investigated. An extended period of accelerated coarsening and a non-monotonic evolution of the normalized size distribution are found. These results are illustrated using approximate asymptotic solutions to the coarsening equation and computer simulations of coarsening dynamics. Experimental results found in silicon nitride systems, which cannot be explained by the classical coarsening theories, are in good agreement with our model predictions.