Characterization of AZ91/alumina nanocomposite produced by FSP

The microstructures, wear property and micro-hardness of AZ91 Mg alloy/alumina particle reinforced nano-composite produced by friction stir processing (FSP) were investigated. The initial microstructures of the AZ91 were composed of irregularly distributed beta-phases (Al(12)Mg(17)), while the FSPed specimens were characterized by the homogeneous distribution of alumina particles, the recrystallized grain structure and the dissolution of beta-phase. The results showed an improvement in the hardness, wear property of the FSPed zone as results of more grain refinement and pinning effect of nano-alumina particles as compared to those of the base metal. The hardness of the FSPed zone was a higher and more homogeneously distributed and the wear resistance as evaluated by Dry sliding wear tests, was superior, as compared with the base metal. (C) 2010 Elsevier B.V. All rights reserved.