First-principles Investigation of the Structural, Electronic and Elastic Properties of Al_2Ca and Al_4Sr Phases in Mg-Al-Ca(Sr) Alloy  

作　　者：杨晓敏 侯华 ZHAO Yuhong YANG Ling HAN Peide 

机构地区：[1]College of Materials Science and Engineering, North University of China [2]College of Materials Science and Engineering, Taiyuan University of Technology

出　　处：《Journal of Wuhan University of Technology(Materials Science)》2014年第5期1049-1056,共8页武汉理工大学学报（材料科学英文版）

基　　金：Funded by the National Natural Science Foundation of China(Nos.51204147,51274175);the International Cooperation Project Supported by Ministry of Science and Technology of China(No.2011DFA50520);the Postgraduate Excellent Innovation Project of Shanxi Province(No.20133105)

摘　　要：First-principles calculations have been carried out to investigate the structural stabilities, electronic structures and elastic properties of Mg17Al12, Al2Ca and Al4Sr phases. The optimized structural parameters are in good agreement with the experimental and other theoretical values. The calculated formation enthalpies and cohesive energies show that Al2Ca has the strongest alloying ability, and Al4Sr has the highest structural stability. The densities of states （DOS）, Mulliken electronic populations, and electronic charge density difference are obtained to reveal the underlying mechanism of structural stability. The bulk modulus, shear modulus, Young＇s modulus, and Poisson＇s ratio are estimated from the calculated elastic constants. The mechanical properties of these phases are further analyzed and discussed. The Gibbs free energy and Debye temperature are also calculated and discussed.First-principles calculations have been carried out to investigate the structural stabilities, electronic structures and elastic properties of Mg17Al12, Al2Ca and Al4Sr phases. The optimized structural parameters are in good agreement with the experimental and other theoretical values. The calculated formation enthalpies and cohesive energies show that Al2Ca has the strongest alloying ability, and Al4Sr has the highest structural stability. The densities of states （DOS）, Mulliken electronic populations, and electronic charge density difference are obtained to reveal the underlying mechanism of structural stability. The bulk modulus, shear modulus, Young＇s modulus, and Poisson＇s ratio are estimated from the calculated elastic constants. The mechanical properties of these phases are further analyzed and discussed. The Gibbs free energy and Debye temperature are also calculated and discussed.

关 键 词：Mg-Al alloys electronic structure elastic properties thermodynamics properties first- principles 

分 类 号：TG146.22[一般工业技术—材料科学与工程]