The strengthening effect of Al atoms into Mg–Al alloy: A first-principles study

Abstract To investigate the strengthening effect of Al atoms into Mg–Al alloy, the tensile and fracture processes of three supercell models Mg 54 , Mg 53 Al and Mg 51 Al 3 (I) were simulated using first-principles calculations. These simulations present directly the strain–stress relationships and the ideal tensile strengths for three models. The results show that the ideal tensile strength for Mg 51 Al 3 (I) noticeably increases but slightly drops for Mg 53 Al, compared with Mg 54 . By means of charge density and density of states analyses, we find that for Mg 51 Al 3 (I), Al atom on the (0 0 0 1) plane draws many electrons from neighbouring Mg atoms, leading to the formation of strong covalent bond between Al and Mg.