Dynamic tensile properties of magnesium nanocomposite

Abstract

In this study, a Mg-6wt%Al alloy and its composite containing 0.22vol% Al 2O 3 nanoparticles are fabricated using a disintegrated melt deposition technique, and samples are subjected to quasi-static and dynamic tension. Compared to quasi-static loading, both materials exhibit significantly higher yield stresses and tensile strengths, much better ductility, and thus a higher energy absorption capacity under dynamic tension. In terms of nano-particle addition, its influence on the mechanical properties are not notable; enhancement of the elastic modulus, yield stress and tensile strength are negligible, and there is a small reduction in ductility. The tensile behaviour obtained in this investigation was compared with results of previous compression tests, and significant tension-compression asymmetry in the response is observed. The tensile yield stress is noticeably larger than that in compression, and the profile of the stress-strain curve for tension differs from that for compression - it is convex upwards for tension, but concave upwards for compression. A possible reason for this asymmetry is the occurrence of twinning in compression and its absence in tension. © 2012 Trans Tech Publications, Switzerland.