论文部分内容阅读
亚稳β′相是Mg-Gd系合金中最有效的沉淀强化相.采用基于密度泛函理论的第一性原理计算研究了Mg-Gd二元合金中β′-Mg7Gd沉淀相的晶格常数、弹性性质以及电子结构.计算结果表明,β′-Mg7Gd与α-Mg基体的晶格错配能够合理解释实验观察到的β′相的形貌.采用弹性常数分析了该相的力学性能及其成键特性.结果表明,β′-Mg7Gd为硬质脆性相.电子结构表明β′-Mg7Gd相中存在强烈的共价键,同时解释了其力学性能.本文的理论计算结果同实验观察的结果吻合.
The metastable β ’phase is the most effective precipitation hardening phase in Mg-Gd alloys.The lattice constants of β’-Mg7Gd precipitates in Mg-Gd binary alloys were calculated by first-principles calculations based on density functional theory , The elastic property and the electronic structure.The calculated results show that the lattice mismatch between β’-Mg7Gd and α-Mg matrix can reasonably explain the morphology of the β ’phase observed experimentally.The mechanical properties of the phase are analyzed by elastic constants and The results show that β’-Mg7Gd is a hard brittle phase.The electronic structure shows that there exists a strong covalent bond in β’-Mg7Gd phase, and its mechanical properties are explained at the same time.The theoretical calculation results of this paper are the same as experimental observations The result is consistent.