Investigating influence of hybrid (yttria + copper) nanoparticulate reinforcements on microstructural development and tensile response of magnesium

Abstract

In the present study, an attempt has been made to tailor the properties of monolithic magnesium by initially reinforcing it with a predetermined amount of nanosize yttria particulates followed by hybridising it with nanocopper particulates in two different volume percentages of 0•3 and 0•6 vol.-% respectively. Both the monolithic magnesium and magnesium nanocomposites were synthesised using the blend press sinter powder metallurgy technique followed by hot extrusion. For sintering of the materials, an innovative hybrid microwave sintering method was chosen with the objective of realising savings in both time and energy. Test results revealed that both strength and ductility of pure magnesium increased with the addition of yttria and a hybrid reinforcement mixture of yttria and copper nanoparticulates. The best combination of properties in uniaxial tension was obtained for the Mg/(0•7Y 2O3+0•3Cu) hybrid nanocomposite. The observed improvement in properties is attributed to synergistic influences of a noticeable reduction in grain size of the hybrid nanocomposite, coexistence of both Y2O3 and copper to a reasonable extent, and a fairly uniform distribution of the reinforcement particulates and intermetallics. A scientific attempt is made in this study to highlight the significance of using hybrid reinforcements, at nanolength scale, in a pure magnesium matrix to obtain a noticeable increase in tensile properties. © 2010 Institute of Materials, Minerals and Mining.