Double-Shelled L1_(2) Nano-structures in Quaternary Al–Er–Sc–Zr Alloys: Origin and Critical Significance  

作　　者：Chao-Min Zhang Pan Xie Yong Jiang Sheng Zhan Wen-Quan Ming Jiang-Hua Chen Ke-Xing Song Hao Zhang 

机构地区：[1]School of Materials Science and Engineering,Henan Key Laboratory of Non-Ferrous Materials Science&Processing Technology,Henan University of Science and Technology,Luoyang 471023,China [2]School of Materials Science and Engineering,Central South University,Changsha 410083,China [3]College of Materials Science and Engineering,Hunan University,Changsha 410082,China [4]Jiangsu Haoran Spray Forming Alloy Co.,Ltd,Zhenjiang 212132,China

出　　处：《Acta Metallurgica Sinica(English Letters)》2021年第9期1277-1284,共8页金属学报（英文版）

基　　金：financial support from the National Natural Science Foundation of China(No.51971249);the Natural Science Foundation of Shandong Province(No.ZR2020KE012)。

摘　　要：The formation of highly coherent double-shelled L1_(2) nano-precipitates in dilute Al–Er–Sc–Zr alloys was investigated with the combined use of Cs-corrected transmission electron microscopy characterization and first-principles energetics calculations. The double-shelled nano-precipitates are primarily featured with an Er-rich core surrounded by a Sc-rich inner shell and a Zr-rich outer shell. First-principles energetics analyses based on the classic homogenous nucleation theory suggested that once forms, this double-shell structure can be thermally stable. The predominant formation of this double-shell structure has thus both profound kinetic and thermodynamic origins. Its formation and stability preference to all other possible L1_(2) nano-structures would become more pronounced as its size increases, no matter what the solute ratio and aging temperature of interest.

关 键 词：Al alloys Core–shell L12 nano-phase FIRST-PRINCIPLES 

分 类 号：TG146.21[一般工业技术—材料科学与工程]