Recrystallized grain size prediction in a particulate reinforced metal matrix composite

Abstract

The recrystallized grain size following cold rolling and annealing of an Al alloy (AA2014) and a particulate reinforced AA2014 composite was investigated. The composite contained 20 vol% alumina particulates of average diameter 15 μm. The recrystallized grain size in the composite was finer than in the alloy, for a given set of conditions; this was most notable for material strained less than 50% cold-work. This behaviour was attributable to a higher nucleation efficiency in the matrix adjacent to coarse alumina particles in the composite. A model was presented for the composite to predict the recrystallized grain size as a function of strain, with respect to the size distribution and number density of alumina particles. This model predicted the strain dependence of the recrystallized grain size and, in particular, the grain size insensitivity to strain at moderate-to-high levels of cold-work.