| Al_2Sr和Mg2sr相结构稳定性与弹性性能的第一原理计算 |
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| 引用本文： | 周惦武,刘金水,徐少华,彭平.Al_2Sr和Mg2sr相结构稳定性与弹性性能的第一原理计算[J].金属学报,2011(10). |
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| 作者姓名： | 周惦武 刘金水 徐少华 彭平 |
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| 作者单位： | 湖南大学汽车车身先进设计制造国家重点实验室;湖南大学材料科学与工程学院; |
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| 基金项目： | 教育部博士点专项科研(新教师)基金项目200805321032; 湖南省自然科学基金项目09JJ6079; 湖南大学汽车车身先进设计制造国家重点实验室自主课题项目71075003资助~~ |
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| 摘 要： | 采用基于密度泛函理论的CASTEP和DMOL程序软件包,计算了Mg_(17)Al_(12),Al_2Sr和Mg_2Sr柏的结构稳定性、弹性性能和电子结构.合金形成热和结合能的计算结果显示,Al_2Sr具有最强的合金化形成能力和结构稳定性.Gibbs自由能的计算结果表明,随着温度的升高,Mg_(17)Al_(12),Al_2Sr和Mg_2Sr的结构稳定性发生了变化,在实际工作温度高于423 K以上时,Al_2Sr的结构稳定性最好,Sr合金化Mg-Al基合金形成Al_2Sr有利于提高镁合金的高温抗蠕变性能.体模量(B)、弹性各向异性系数(A)、Young's模量(E)、剪切模量(G)和Poisson比(v)的计算结果表明,Mg2Sr为延性相,而Mg_(17)Al_(12)和Al_2Sr为脆性相,Mg_2Sr的塑性最好.态密度和Mulliken电子占据数的计算结果表明,Al_2Sr结构最稳定的原因主要源于体系存在强烈的共价键作用,而Mg_(17)Al_(12)结构隐定性优于Mg_2Sr是体系中离子键与共价键共同作用的结果.
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| 关 键 词： | 镁合金 第一原理计算 电子结构 结构稳定性 弹性性能 |
FIRST-PRINCIPLE CALCULATIONS OF STRUCTURAL STABILITIES AND ELASTIC PROPERTIES OF Al_2Sr AND Mg_2Sr PHASES |
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| ZHOU Dianwu State Key Laboratory of Advanced Design , Manufacturing for Vehicle Body,Hunan University,Changsha LIU Jinshui,XU Shaohua,PENG Ping School of Materials Science , Engineering,Changsha.FIRST-PRINCIPLE CALCULATIONS OF STRUCTURAL STABILITIES AND ELASTIC PROPERTIES OF Al_2Sr AND Mg_2Sr PHASES[J].Acta Metallurgica Sinica,2011(10). |
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| Authors: | ZHOU Dianwu State Key Laboratory of Advanced Design Manufacturing for Vehicle Body Hunan University Changsha LIU Jinshui XU Shaohua PENG Ping School of Materials Science Engineering Changsha |
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| Affiliation: | ZHOU Dianwu State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body,Hunan University,Changsha 410082 LIU Jinshui,XU Shaohua,PENG Ping School of Materials Science and Engineering,Changsha 410082 |
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| Abstract: | Structural stabilities,elastic properties and electronic structures of Mg_(17)Al_(12),Al_2Sr and Mg_2Sr phases have been determined from first principle calculations by using CASTEP and DMOL programs based on the density functional theory.The calculated formation heats and cohesive energies indicated that Al_2Sr has the strongest alloying ability as well as the highest structural stability.The calculated Gibbs free energy showed that the structural stabilities of Mg_(17)Al_(12),Al_2Sr and Mg_2Sr change with... |
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| Keywords: | magnesium alloy first-principle calculation electronic structure structural stability elastic property |
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