Formation and growth of precipitates in a Mg-7Gd-5Y-1Nd-2Zn-0.5Zr alloy aged at 200 °C

被引：9
作者：
Du, Zhiwei [1 ,2 ,6 ]
Peng, Yonggang [1 ,2 ,6 ]
Teng, Hang [3 ]
Cao, Zhong [4 ]
Zhang, Kui [5 ]
Ma, Minglong [5 ]
Han, Xiaolei [1 ,2 ]
Li, Ting [1 ,2 ]
Che, Cong [1 ,2 ]
Li, Yongjun [1 ,2 ]
机构：
[1] Guobiao Beijing Testing & Certificat Co Ltd, Beijing 100088, Peoples R China
[2] China United Test & Certificat Co Ltd, Beijing 100088, Peoples R China
[3] Nanjing Yunhai Special Met Co Ltd, Nanjing 211212, Peoples R China
[4] Shanghai Spaceflight Precis Machinery Inst, Shanghai 201600, Peoples R China
[5] GRIMAT Engn Inst Co Ltd, State Key Lab Nonferrous Met & Proc, Beijing 101407, Peoples R China
[6] Guobiao Beijing Testing & Certificat Co Ltd, 11, St Xingkedong, Beijing 110407, Peoples R China
来源：
JOURNAL OF MAGNESIUM AND ALLOYS | 2023年 / 11卷 / 07期
基金：
中国国家自然科学基金;
关键词：
Magnesium alloys; Aging; Precipitates; Microstructures; HAADF-STEM; MG-GD; WT.PERCENT ALLOY; BUILDING-BLOCK; CAST ALLOYS; EVOLUTION; MAGNESIUM; PHASE; MICROSTRUCTURE; CLUSTERS;
D O I：
10.1016/j.jma.2022.10.012
中图分类号：
TF [冶金工业];
学科分类号：
0806 ;
摘要：
Crystal structures, growth characteristics, and transformation of the precipitates in a Mg-7Gd-5Y-1Nd-2Zn-0.5Zr (wt.%) alloy aged at 200 degrees C for various durations were investigated using transmission electron microscopy (TEM) and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). A detailed Mg-Gd type precipitation sequence for Mg-Gd-Y-Nd-Zn alloys was proposed as follows: supersaturated solid solution. solute clusters. zigzag GP zones + beta ''(I). beta' -> beta' + protrusions/joints. pre- beta(1) -> beta(1) -> beta. Solute clusters formed in the early stage of aging consisted of one or more rare-earth (RE)/Zn-rich atomic columns with different configurations. RE/Zn-rich solute clusters grew into zigzag GP zones and beta ''(I) as aging time extending. The paired-zigzag GP zones might grow up to be beta' precipitates directly. In the peak- and plat-aging stages, the number of solute clusters in the matrix decreased until they disappeared, and most existed as zigzag arrays and super hexagons. Protrusions formed at the end of beta' at an angle of 120 degrees, then grew into joints when two different beta' variants encountered together. Protrusions/joints comprise zigzag arrays, super-hexagons, beta'(F), beta '' (II), beta(T), and hybrid structures rich in solute atoms, and act as catalysts for the growth of the beta' variants. Larger beta' grow by joints consumption while smaller beta' precipitates dissolve to form joints. beta(1) precipitates essentially evolve from pre-beta(1) precipitates, with four-point diamond structures formed by RE/Zn atomic substitution and atomic migration based on the original alpha-Mg structure. (c) 2022 Chongqing University. Publishing services provided by Elsevier B.V. on behalf of KeAi Communications Co. Ltd.
引用
收藏
页码：2326 / 2339
页数：14
相关论文
共 39 条
[1]  
Bu D.H., 2022, Study on Microstructure and Mechanical Properties of WE71 Magnesium Alloy Cylindrical Parts
[2]   Evolution of LPSO phases in a Mg-Zn-Y-Gd-Zr alloy during semi-continuous casting, homogenization and hot extrusion [J].
Chen, Tao ;
Chen, Zhiyong ;
Shao, Jianbo ;
Wang, Renke ;
Mao, Longhui ;
Liu, Chuming .
MATERIALS & DESIGN, 2018, 152 :1-9
[3]   Microstructure evolution in a Mg-15Gd-0.5Zr (wt.%) alloy during isothermal aging at 250°C [J].
Gao, X. ;
He, S. M. ;
Zeng, X. Q. ;
Peng, L. M. ;
Ding, W. J. ;
Nie, J. F. .
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, 2006, 431 (1-2) :322-327
[4]   Precipitation in a Mg-10Gd-3Y-0.4Zr (wt.%) alloy during isothermal ageing at 250°C [J].
He, S. M. ;
Zeng, X. Q. ;
Peng, L. M. ;
Gao, X. ;
Nie, J. F. ;
Ding, W. J. .
JOURNAL OF ALLOYS AND COMPOUNDS, 2006, 421 (1-2) :309-313
[5]   Effect of Zn additions on the age-hardening of Mg-2.0Gd-1.2Y-0.2Zr alloys [J].
Honma, T. ;
Ohkubo, T. ;
Kamado, S. ;
Hono, K. .
ACTA MATERIALIA, 2007, 55 (12) :4137-4150
[6]  
Honma T, 2005, MAT SCI ENG A-STRUCT, V395, P301, DOI 10.1016/j.msea.2004.12.035
[7]   A Review on Developments in Magnesium Alloys [J].
Kaya, A. Arslan .
FRONTIERS IN MATERIALS, 2020, 7
[8]   The role of metastable LPSO building block clusters in phase transformations of an Mg-Y-Zn alloy [J].
Kim, Jin-Kyung ;
Ko, Won-Seok ;
Sandloebes, Stefanie ;
Heidelmann, Markus ;
Grabowski, Blazej ;
Raabe, Dierk .
ACTA MATERIALIA, 2016, 112 :171-183
[9]   Nano-precipitates made of atomic pillars revealed by single atom detection in a Mg-Nd alloy [J].
Lefebvre, W. ;
Kopp, V. ;
Pareige, C. .
APPLIED PHYSICS LETTERS, 2012, 100 (14)
[10]  
Li M., 2016, STUDY MICROSTRUCTURE
1234