高强度 Al-Zn-Mg 合金的强化机制和析出演变的理论研究。

Theoretical investigation of the strengthening mechanism and precipitation evolution in high strength Al-Zn-Mg alloys.

机构信息

Materials Computation Center, General Research Institute for Nonferrous Metals, Beijing 100088, China.

State Key Laboratory of Nonferrous Metals and Processes, General Research Institute for Nonferrous Metals, Beijing 100088, China.

出版信息

Phys Chem Chem Phys. 2018 May 16;20(19):13616-13622. doi: 10.1039/c8cp01820k.

DOI:10.1039/c8cp01820k

PMID:29737340

Abstract

Density-functional theory calculations have been performed to systematically investigate the behaviors of solute atoms in 7000 series Al-Zn-Mg based alloys. It is found that solute atoms Mg and Zn are likely to segregate to the Σ5(210)[001] tilt Al GB. The bonding environment and interface cohesion will be affected to different degrees. Also, for GPI(100) our calculations indicate that a Zn/Mg/Zn sandwich configuration in the Al matrix (100) planes is energetically favorable. However, for GPII(111) the disordered structure turns out to be the most stable one. It mainly results from strong 3d-3s hybridization interactions between Zn and Mg atoms. Furthermore, the properties of the metastable phase η' and the equilibrium phase η have also been addressed. The present study provides valuable insight for developing Al alloys with superior performance.

摘要

已运用密度泛函理论对 7000 系列 Al-Zn-Mg 基合金中溶质原子的行为进行了系统研究。研究发现，溶质原子 Mg 和 Zn 很可能会偏析到 Σ5(210)[001]倾斜 Al 晶界。这将对界面结合能和界面结合产生不同程度的影响。此外，对于 GPI(100)，我们的计算表明，在 Al 基体（100）面中 Zn/Mg/Zn 三明治结构是能量有利的。然而，对于 GPII(111)，无序结构则是最稳定的。这主要是由于 Zn 和 Mg 原子之间强烈的 3d-3s 杂化相互作用所致。此外，还研究了亚稳相 η'和平衡相 η的性质。本研究为开发具有优异性能的 Al 合金提供了有价值的见解。