Temperature dependence of abnormal grain growth in pure magnesium

Abstract

In this work, grain growth characteristics of as-extruded pure magnesium was investigated for samples annealed at temperatures ranging from 300 °C to 450 °C for different times. The grain growth exponent of n = 4, indicating rapid coarsening, was determined. A normal grain growth behavior was observed both at low and high annealing temperatures. However, at intermediate annealing temperature, an abnormal grain growth was recorded. This temperature dependence of grain growth behavior was attributed to competition between dislocation density gradient and grain boundary mobility.