First-principles calculation on the thermodynamic and elastic properties of precipitations in Al-Cu alloys

被引：27

作者：

Sun, Dongqiang ^{[1
]}

Wang, Yongxin ^{[1
]}

Zhang, Xinyi ^{[1
]}

Zhang, Minyu ^{[1
]}

Niu, Yanfei ^{[1
]}

机构：

[1] Northwestern Polytech Univ, Sch Mat, State Key Lab Solidificat Proc, Xian 710072, Peoples R China

来源：

SUPERLATTICES AND MICROSTRUCTURES | 2016年 / 100卷

基金：

中国国家自然科学基金;

关键词：

First-principles; Aluminium alloys; Mechanical properties; Ideal tensile strength; MECHANICAL-PROPERTIES; ELECTRON-MICROSCOPY; EVOLUTION; SC; APPROXIMATION; PHASE; ZONES; ZR; TI;

D O I：

10.1016/j.spmi.2016.09.012

中图分类号：

O469 [凝聚态物理学];

学科分类号：

070205 ;

摘要：

First-principles calculations based on density functional theory was used to investigate the structural, thermodynamic and elastic properties of precipitations, theta '', theta' and theta, in Al-Cu alloys. The values of lattice constants accord with experimental results well. The structural stability of theta is the best, followed by theta' and theta ''. In addition, due to the highest bulk modulus, shear modulus and Young's modulus, theta possesses the best reinforcement effect in precipitation hardening process considered only from mechanical properties of perfect crystal. According to the values of B/G, Poisson's ratio and C-11-C-12, theta' has the worst ductility, while theta '' has the best ductility, the ductility of theta is in the middle. The ideal tensile strength of theta '', theta' and theta calculated along 11001 and [001] directions are 20.87 GPa, 23.11 GPa and 24.70 GPa respectively. The analysis of electronic structure suggests that three precipitations all exhibit metallic character, and number of bonding electrons and bonding strength are the nature of different thermodynamic and elastic properties for theta '', theta' and theta. (C) 2016 Elsevier Ltd. All rights reserved.

引用

页码：112 / 119

页数：8

共 42 条

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