Grain growth kinetics of a fine-grained AZ31 magnesium alloy produced by hot rolling

A study on the kinetics of grain growth of a fine-grained, hot-rolled AZ31 magnesium alloy was carried out by isothermal and isochronal annealing treatments. The grain size of the as-rolled and subsequently annealed sheet samples was determined by metallographic observation using the linear intercept method. It was found that for annealing at temperature in the range of 523–723 K, the effect of annealing temperature, T, and time, t  , on the grain growth could be well interpreted by the kinetic equation, Dn−D0n=kt, where k=k0e−Eg/RTk=k0e−Eg/RT. Based on the experimental data on grain growth obtained by annealing treatments, the grain growth exponent, n, and the activation energy, Eg, were figured out, and these grain growth kinetic parameters were compared with those for other magnesium alloys reported in recent literatures.