Crystallization model of magnesium primary phase in the AZ91/SiC composite

Metal–matrix composites are widely applied in the aerospace and automotive industries because of their low density and high rigidity. We focus on composites of magnesium-alloy (AZ91) matrix reinforced with SiC particles, with the aim of building a micro–macro model for their solidification. Heat-flow processes are modelled on the macro-scale, with latent heat release during nucleation and grain growth. Calculations are for a fixed cooling rate, consistent with the micromodel for magnesium primary phase solidification. The population density of grains in the matrix is assumed to depend on the maximum supercooling and on the mass fraction of SiC particles. The present model gives reasonable agreement with measurements.