Lath-like phases formed at an extremely high temperature in a Mg-RE(RE=rare earth)-Al alloy  

作　　者：Bo Deng Shu-Hui Lv Qiang Yang Dong-Yue Zhao Jun-Yuan Fan Xin Qiu 

机构地区：[1]School of Materials Science and Engineering,Changchun University of Science and Technology,Changchun 130022,China [2]State Key Laboratory of Rare Earth Resource Utilization,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences,Changchun 130022,China [3]Chongqing Research Institute,Changchun University of Science and Technology,Chongqing 401135,China

出　　处：《Rare Metals》2024年第8期3937-3945,共9页稀有金属（英文版）

基　　金：financially supported by the Scientific and Technological Developing Scheme of Jilin Province(Nos.YDZJ202301ZYTS538 and 20220101239JC);the Chinese Academy of Sciences Youth Innovation Promotion Association (No.2023234);the National Natural Science Foundation of China (No.U21A20323);the Scientific and Technological Developing Scheme of Jilin Province (No.SKL202302038);the Major Scientific and Technological Projects of Hebei Province (No.23291001Z);the Scientific and Technology Project of Hanjiang District。

摘　　要：Thermal stable intermetallic particles are important for the heat resistance of magnesium(Mg)alloys.In this work,many lath-like particles formed in α-Mg grains of a Mg-8Gd-3Sm-0.7Al casting alloy when heat-treated at 873 K.Atomic-resolution high-angle annular dark field scanning transmission electron microscopy(HAADF-STEM) characterizations indicate that most of them are Mg-containing Al_(2)(Gd,Sm),with the atomic ratio of Mg:Al:(Gd,Sm) being ~1:1:1;a small part of them with relatively wider thickness are long-period stacking ordered(LPSO) phases simultaneously containing both 14H and 18R structures.Both followed common orientation relationships with Mg matrix as those reported in previous work.In addition,many Mg laths were observed in the primary blocky Al_(2)(Gd,Sm) phase at grain boundaries,where the atomic ratio of Al:(Gd,Sm) in the Al_(2)(Gd,Sm) matrix was 2:1.Finally,density functional theory(DFT) calculations illustrated the detail structure of the re-constructed Mg/Al_(2)RE interface and simultaneously deduced the underlying reason for the re-dissolution of the newly formed Mg-containing Al_(2)(Gd,Sm) plates in α-Mg matrix.

关 键 词：Magnesium alloy HAADF-STEM Microstructures Intermetallic particles Orientation relationships Interfaces 

分 类 号：TG146.22[一般工业技术—材料科学与工程]