(Si2-xAlx)Hf在铝硅镁铪合金中的析出

Precipitation of (Si2-xAlx)Hf in an Al-Si-Mg-Hf Alloy.

作者信息

Wang Xueli, Xie Zhiqiang, Huang Huilan, Jia Zhihong, Yang Guang, Gu Lin, Liu Qing

机构信息

1College of Materials Science and Engineering,Chongqing University,Chongqing 400044,China.

2Electronic Materials Research Laboratory,Key Laboratory of the Ministry of Education and International Center for Dielectric Research,Xi'an Jiaotong University,Xi'an 710049,China.

出版信息

Microsc Microanal. 2017 Aug;23(4):724-729. doi: 10.1017/S1431927617000678. Epub 2017 Jun 20.

DOI:10.1017/S1431927617000678

PMID:28629490

Abstract

The morphology, composition, and structure of precipitates in an Al-Si-Mg-Hf alloy after heat treatment at 560°C for 20 h were studied by means of C s -corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), energy dispersive X-ray spectrometry (EDS), high-resolution transmission electron microscopy (HRTEM), and first-principle calculations. Precipitates with three kinds of morphologies were observed. The rectangular and square precipitates were predominantly (Si2-x Al x )Hf phases, while the nanobelt-like precipitate is the Si2Hf phase. First-principle calculations were used to show that the Si6 and Si8 sites were the most favorable sites for Al incorporation in the orthorhombic Si2Hf phase.

摘要

采用 Cs 校正的高角度环形暗场扫描透射电子显微镜（HAADF-STEM）、能量色散 X 射线光谱仪（EDS）、高分辨率透射电子显微镜（HRTEM）和第一性原理计算方法，研究了 Al-Si-Mg-Hf 合金在 560°C 下热处理 20 小时后析出相的形貌、成分和结构。观察到三种形貌的析出相。矩形和方形析出相主要是(Si2-xAlx)Hf 相，而纳米带状析出相是 Si2Hf 相。第一性原理计算表明，在正交 Si2Hf 相中，Si6 和 Si8 位点是 Al 掺入的最有利位点。