Using integrated hybrid (Al plus CNT) reinforcement to simultaneously enhance strength and ductility of magnesium

Magnesium nano-composites containing hybrid aluminium-carbon nanotube (Al-CNT) reinforcement were synthesized through powder metallurgy route using microwave assisted rapid sintering technique followed by hot extrusion. Compared to monolithic Mg, microstructural characterization revealed reasonably uniform distribution of Al-CNT particles in the matrix and reduction in average matrix grain size in the case of hybrid nano-composites. Compared to monolithic Mg, the Mg/Al-CNT nano-composites exhibited higher elastic modulus, strength and failure strain up to 1.00 wt.% Al content. The CNT content was kept constant at 0.18 wt.%. Among the different nano-composite formulations, the Mg/1.00Al-0.18CNT nano-composite exhibited the best improvement in elastic modulus (E), tensile yield strength (0.2%YS), ultimate tensile strength (UTS) and failure strain (up to +3.6%, +38%, +36% and +42%, respectively) compared to pure Mg. The effect of hybrid Al-CNT reinforcement integration on the enhancement of mechanical properties of Mg is investigated in this paper. (C) 2011 Elsevier Ltd. All rights reserved.