Ag微合金化对Al-Mg-Si合金析出相结构的影响
Effects of Ag Microalloying on Precipitated Phase Structure of Al-Mg-Si Alloy
王茹 1邱铨强 1吴蔚 1袁悠悠 1翁瑶瑶 2刘玉爽2
作者信息
- 1. 南京工程学院材料科学与工程学院,南京 211100
- 2. 南京工程学院材料科学与工程学院,南京 211100;南京工程学院江苏省先进结构材料与应用技术重点实验室,南京 211100
- 折叠
摘要
采用第一性原理计算和球差矫正透射电子显微分析,从形成焓、电荷密度和原子尺度微观结构等方面对Al-Mg-Si-Ag合金的析出相结构进行研究.结果表明,Ag微合金化后β″相的稳定性降低,Ag原子倾向于偏聚在β″相/基体界面处,这主要是由于Ag对电子的攫取作用;Ag微合金化后形成的β′相结构更为稳定,Ag原子能够进入β′相内部占据其Si1和Si2位置,且形成焓均低于β″相,促进β″相转变为β′相,这与Ag-Al原子间的强共价键有关;Ag微合金化对β相的结构稳定性不利,这主要是Ag-Mg原子间的弱键强导致的.
Abstract
The precipitated phase structure of Al-Mg-Si-Ag alloy was systematically investigated by first-principles calculation and spherical aberration corrected transmission electron microscopy in aspects of formation enthalpy,charge density and atomic scale microstructure.The results indicate that the stability of β″ phase is decreased after Ag microal-loying,and Ag atoms tend to segregate at the β″ phase/matrix interface,which is mainly attributed to the electron grabbing effect of Ag.Ag microalloying is beneficial to the structural stability of β′ phase.Ag atoms can enter the inte-rior of β′ phase,possibly occupying the Si1 and Si2 positions,and the formation enthalpy is lower than that of β″phase,promoting the transformation of β″ phase into β′ phase,which is related to the strong covalent bond between Ag-Al atoms.Ag microalloying is adverse to the structural stability of β phase,which results from the weak bond strength between Ag-Mg atoms.
关键词
Al-Mg-Si合金/Ag微合金化/析出相/第一性原理计算/HAADF-STEMKey words
Al-Mg-Si Alloy/Ag Microalloying/Precipitated Phase/First-principles Calculation/HAADF-STEM引用本文复制引用
基金项目
国家自然科学基金青年基金资助项目(52101141)
南京工程学院引进人才科研启动基金资助项目(YKJ202005)
出版年
2024
NETL
NSTL
万方数据