Hybridizing boron carbide (B4C) particles with aluminum (Al) to enhance the mechanical response of magnesium based nano-composites

Abstract

In this work, we synthesized and investigated the mechanical performance of magnesium (Mg) nano-composites containing either B4C or hybrid Al-B4C particles (B4C particles hybridized with Al using ball milling) synthesized through powder metallurgy route using microwave assisted rapid sintering technique followed by hot extrusion. Compared to monolithic Mg, microstructural characterizations revealed presence of porosity along the particles boundaries and reduction in average matrix grain size. Among the different nano-composite formulations, the Mg/0.66B4C nano-composite exhibited the best improvement, though marginal, in tensile yield strength (0.2% YS), compressive yield strength (0.2% CYS), ultimate tensile strength (UTS), ultimate compressive strength (UCS) and tensile failure strain (FSt) (up to +10%, +7.5%, +2%, +36%, and 12%, respectively) compared to pure Mg while compressive failure strain (FSc) was compromised. To improve the mechanical response of Mg/B4C nano-composites further, the best observed B4C content was hybridized with Al to outcome hybrid Al-B4C particles. The effect of presence of hybridized B 4C particles with Al (Al-B4C) in the case of hierarchical Mg/0.92Al-0.66B4C configuration exhibits an improvement of +8.3% (0.2% YS), +29% (0.2% CYS), +45% (UTS) and +6.2 (UCS) compared to its Mg/0.66B4C nano-composite counterpart whereas both FSt and FSc were compromised. Considering the crystallographic texture, the effect of presence of B4C particles (either solely or as hybrid particle forms) on textural evolution of Mg is also investigated here. © 2012 Elsevier B.V. All rights reserved.