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Affiliation of Author(s):材料科学与技术学院

Journal:BULLETIN OF MATERIALS SCIENCE

Key Words:First-principles Mg solid solution solid solution strengthening Er Al

Abstract:To study the solid solution strengthening effect on magnesium (Mg)-X (X = Al, Er) alloys, supercell models of Mg, Mg35Er and Mg35Al are established to perform the first-principles pseudopotential plane wave calculations based on density functional theory. The calculated cohesive energy of Mg35Er is lower than that of Mg35Al. This indicates that Mg35Er has better structural stability than Mg35Al. The bulk modulus, Young's modulus and shear modulus of the solid solutions increases simultaneously when Al and Er are doped into the Mg matrix. Moreover, the solid solution strengthening of Er is much higher than the Al containing alloy. The order of toughness of the three solutions from the highest to the lowest is Mg, Mg35Er and Mg35Al, while the order of increasing elastic anisotropy is in the reverse order. The number of bonding electrons of Mg35Er in the low-energy region of the Fermi level is much higher than that of Mg35Al, and the density of states of Mg35Er at the Fermi level is higher than that of Mg35Al. Compared with Al atoms, Er atoms share more electric charges with Mg atoms, which leads to an increasingly uniform charge distribution around Er atoms.

ISSN No.:0250-4707

Translation or Not:no

Date of Publication:2019-02-01

Co-author:Liu Zili,Liu, Guodong,Wang, Wenjing,Li, Jian

Correspondence Author:lxq