Role of Mg in simultaneously improving the strength and ductility of Al–Mg alloys

Abstract

We found that when Mg is added to Al in small amounts, it results in alloys that exhibit both significantly higher strength and ductility than those of the pure Al counterpart. Strength and plasticity are contrasting properties for most crystalline alloys; as such, the simultaneous improvement of these properties seems contradictory from the viewpoint of dislocation motion. Comparative studies of Al–xMg alloys containing different amounts of Mg were performed to elucidate how these apparently mutually exclusive properties were improved simultaneously; microstructural observations were made using X-ray diffractometry and transmission electron microscopy to assess the effect of Mg on the strength and ductility on the alloys, while molecular dynamics simulations were performed to comprehensively understand how the resulting high-strength alloys could also exhibit high ductility.