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

To investigate the strengthening effect of All atoms into Mg-Al alloy, the tensile and fracture processes of three supercell models Mg-54, Mg53Al and Mg51Al30(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 Mg51Al3(I) noticeably increases but slightly drops for Mg53Al, compared with Mg-54. By means of charge density and density of states analyses, we find that for Mg51Al3(I), Al atom on the (0001) plane draws many electrons from neighbouring Mg atoms, leading to the formation of strong covalent bond between Al and Mg. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.