The electronic origin of strengthening and ductilizing magnesium by solid solutes

Electron work function (EWF) is a simple and fundamental parameter which largely reflects or characterizes the behavior of electrons in metals. This parameter can be used to guide the selection of solutes for effective modification of mechanical properties of Mg, an important metal for lightweight materials. From our prediction, adding solutes with EWFs lower than that of Mg can improve both strength and ductility of Mg, while adding elements with higher EWFs results in higher strength but lowered ductility. This study reveals the electronic origin of such influences of solutes on the strength and ductility of Mg and suggests an EWF-based principle or law for selecting appropriate solutes to achieve the optimal combination of strength and ductility for advanced Mg alloys. (C) 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.