Kinetics of grain growth in nanocrystalline magnesium-based metal-metal composite synthesized by mechanical alloying

Nanocrystalline (nc) Mg-5 wt%-Al and Mg-5 wt%-Al-10.3 wt%-Ti metal-metal composites have been synthesized by mechanical alloying (MA) for 20 h of milling duration. XRD was employed as analysis tool for the structural evolution during MA and thermal stability at elevated temperatures. Kinetics of grain growth of Mg-5 wt%-Al-10.3 wt%-Ti and Mg-5 wt%-Al systems under isothermal and isochronal annealing was investigated. The results showed that the grain growth behavior can be described by the parabolic kinetic equation of grain growth and the activation energy of mechanically alloyed metal-metal composite is higher than that of cast Mg alloy and that of its base metal of Mg-5 wt%-Al. (c) 2005 Elsevier Ltd. All rights reserved.