7475铝合金中η相沿E/Al相界的非均匀析出机理  

Heterogeneous Precipitation Mechanism of η Phase at E/Al Interface in 7475 Aluminum Alloy

作　　者：李茂华 杨延清[3] 陈志龙[1] 宋宇峰 唐昌平 Li Maohua;Yang Yanqing;Chen Zhilong;Song Yufeng;Tang Changping(School of Materials Science and Engineering,Hunan University of Science and Technology,Xiangtan 411201,China;Key Laboratory of High Temperature Wear Resistant Materials Preparation Technology of Hunan Province,Hunan University of Science and Technology,Xiangtan 411201,China;School of Materials Science and Engineering,Northwestern Polytechnical University,Xi’an 710072,China)

机构地区：[1]湖南科技大学材料科学与工程学院,湖南湘潭411201 [2]湖南科技大学高温耐磨材料及制备技术湖南省国防科技重点实验室,湖南湘潭411201 [3]西北工业大学材料学院,陕西西安710072

出　　处：《稀有金属材料与工程》2022年第7期2483-2489,共7页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(52075167);湖南省自然科学基金(2020JJ4307);湖南省教育厅优秀青年基金(19B214)。

摘　　要：采用高分辨透射电镜(HRTEM)和高角环形暗场扫描透射电镜(HAADF-STEM)中的三维重构技术,研究了7475铝合金中η相沿E/Al相界的非均匀析出行为及其形核和生长机理。结果表明,η相在不同的E相颗粒(具有不同形态和不同体积)或同一个E相颗粒的界面析出时,其形核位置、形核率、生长速率和形态有很大差异。E相的界面能和弹性应变能是η相在E/Al相界形核、生长和粗化的决定性因素。η相长大属于扩散控制转变,主要通过相界高速扩散传输溶质原子。The heterogeneous precipitation behavior and nucleation and growth mechanisms of η phase at E/Al interfaces in 7475aluminum alloy were studied using high resolution transmission electron microscopy(HRTEM) and 3D reconstruction technique in high angle annular dark field scanning transmission electron microscopy(HAADF-STEM). It is found that the nucleation location, nucleation rate, growth rate and morphology of η phase are greatly different when η phase are formed at E particles with different morphology and volume or the same E particle. The decisive factors that affect the nucleation, growth and coarsening of η phase are the interface energy and elastic strain energy of E phase. The growth of η phase belongs to the diffusion-controlled transformation. Solute atoms are transferred by the interphase interface diffusion at a high speed.

关 键 词：7475铝合金 E/Al相界 非均匀析出 相变机理 

分 类 号：TG146.21[一般工业技术—材料科学与工程]