Enhancing tensile and compressive strengths of magnesium using nanosize (Al 2O 3 + Cu) hybrid reinforcements

Abstract

This study investigates the microstructure and mechanical properties of magnesium (Mg) containing alumina (Al 2O 3) and copper (Cu) nanoparticles as hybrid reinforcements. For composite preparation, the amount of Cu was varied from 0.1 to 0.9 volume percent, whereas the amount of Al 2O 3 was fixed at 1 volume percent. Mg and its composites were synthesized using powder metallurgy route incorporating energy-efficient microwave sintering followed by hot extrusion. Hybrid reinforcements in Mg matrix led to a grain size reduction, and the grain size decreased with increasing presence of secondary phases (reinforcements and intermetallics). Overall distribution of secondary phases within the matrix was observed to be uniform despite the formation of clusters. A significant improvement in microhardness was exhibited by all composite formulations when compared to pure Mg. The results also showed that yield and ultimate strengths were enhanced in all composite formulations under both tensile and compressive loading while tensile and compressive failure strains were compromised. © The Author(s) 2011 Reprints and permissions: http://www.sagepub.co.uk/journalsPermissions.nav.