Synthesis and analysis of Mg–3%Al alloy nanocomposites reinforced by RGO

Abstract

ABSTRACT Graphene and its derivatives, due to their extraordinary mechanical, thermal, and tribological properties, are extensively used to fabricate bulk graphene-based nanocomposites. On the other hand, magnesium alloys are lightweight and manifest excellent mechanical properties. In the present study, the hardness and compressive responses of Mg–3 wt%Al/xRGO (x = 0.1 wt% and 0.3 wt.%) nanocomposites at ambient temperature were investigated. Further, the coefficient of thermal expansion of Mg–3 wt%Al/xRGO (x = 0.1 wt% and 0.3 wt.%) nanocomposites at elevated temperatures were estimated and compared with those of pure Mg and Mg–3 wt%Al alloy. Reduced graphene oxide (RGO) synthesized through the improved Hummer’s Method followed by the thermal reduction method was used as the reinforcement material. The bulk samples of pure Mg, Mg–3%Al alloy, and nanocomposites were synthesized by blending of Mg, Al and RGO powder followed by cold compaction, microwave sintering and hot extrusion. Nanocomposite samples displayed significant changes in microstructures and substantial improvements in both Vickers hardness and ultimate compressive strength. The lower thermal expansion coefficients of Mg–3%Al/xRGO (x = 0.1 wt% and 0.3 wt.%) nanocomposites demonstrated better thermal and dimensional stability with respect to temperature. The obtained results would be conducive to design lightweight structural materials.