Creep Behavior and Microstructure Evolution of Sand-Cast Mg-4Y-2.3Nd-1Gd-0.6Zr Alloy Crept at 523-573 K

IMR OpenIR

	Creep Behavior and Microstructure Evolution of Sand-Cast Mg-4Y-2.3Nd-1Gd-0.6Zr Alloy Crept at 523-573 K
	Kang, Y. H.; Yan, H.; Chen, R. S.; Yan, H; Chen, RS (reprint author), Chinese Acad Sci, Inst Met Res, Grp Magnesium Alloys & Their Applicat, Shenyang 110016, Peoples R China.
	2017
发表期刊	JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
ISSN	1005-0302
卷号	33 期号:1 页码:79-89
摘要	High temperature tensile-creep behavior of Mg-4Y - 2.3Nd - 1Gd - 0.6Zr (wt%, WE43(T6)) alloy at 523-573 K was investigated. The creep stress exponent is equal to 4.6, suggesting the underlying dislocation creep mechanism. The activation energy is (199 +/- 23) kJ/mol, which is higher than that for sel-fdiffusion in Mg and is believed to be associated with precipitates coarsening or cross slip. The creep mechanism is further suggested to be dislocation climb at 523 K, while a cross slip at 573 K is possible. The metastable beta' and beta(1) phases in the WE43(T6) alloy were relatively thermal stable at 523 K and could be effective to hinder the dislocation climb, which contributed to its excellent creep resistance. However, at 573 K it readily transforms into equilibrium beta(e) phase and coarsens within two hours, thereby causing a decrease of creep resistance. In addition, precipitate free zones approximately normal to applied stress direction (directional PFZs) developed during the creep deformation, especially at 573 K. Those zones became preferential sites to nucleate, extend and connect microcracks and cavities, which lead to the intergranular creep fracture. Improving the thermal stability of precipitates or introducing thermally stable fine plate-shaped precipitates on the basal planes of Mg matrix could enhance the high temperature creep resistance. Copyright (C) 2017, The editorial office of Journal of Materials Science & Technology. Published by Elsevier Limited.; High temperature tensile-creep behavior of Mg-4Y - 2.3Nd - 1Gd - 0.6Zr (wt%, WE43(T6)) alloy at 523-573 K was investigated. The creep stress exponent is equal to 4.6, suggesting the underlying dislocation creep mechanism. The activation energy is (199 +/- 23) kJ/mol, which is higher than that for sel-fdiffusion in Mg and is believed to be associated with precipitates coarsening or cross slip. The creep mechanism is further suggested to be dislocation climb at 523 K, while a cross slip at 573 K is possible. The metastable beta' and beta(1) phases in the WE43(T6) alloy were relatively thermal stable at 523 K and could be effective to hinder the dislocation climb, which contributed to its excellent creep resistance. However, at 573 K it readily transforms into equilibrium beta(e) phase and coarsens within two hours, thereby causing a decrease of creep resistance. In addition, precipitate free zones approximately normal to applied stress direction (directional PFZs) developed during the creep deformation, especially at 573 K. Those zones became preferential sites to nucleate, extend and connect microcracks and cavities, which lead to the intergranular creep fracture. Improving the thermal stability of precipitates or introducing thermally stable fine plate-shaped precipitates on the basal planes of Mg matrix could enhance the high temperature creep resistance. Copyright (C) 2017, The editorial office of Journal of Materials Science & Technology. Published by Elsevier Limited.
部门归属	[kang, y. h. ; yan, h. ; chen, r. s.] chinese acad sci, inst met res, grp magnesium alloys & their applicat, shenyang 110016, peoples r china ; [kang, y. h.] univ chinese acad sci, beijing 100049, peoples r china
关键词	We43 Alloy Creep Pfzs Precipitate Fracture
学科领域	Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering
资助者	National Basic Research Program of China [2013CB632202, 51531002]; National Natural Science Foundation of China [51301173]
收录类别	SCI
语种	英语
WOS记录号	WOS:000396351100010
引用统计	被引频次：33[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/78362
专题	中国科学院金属研究所
通讯作者	Yan, H; Chen, RS (reprint author), Chinese Acad Sci, Inst Met Res, Grp Magnesium Alloys & Their Applicat, Shenyang 110016, Peoples R China.
推荐引用方式 GB/T 7714	Kang, Y. H.,Yan, H.,Chen, R. S.,et al. Creep Behavior and Microstructure Evolution of Sand-Cast Mg-4Y-2.3Nd-1Gd-0.6Zr Alloy Crept at 523-573 K[J]. JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY,2017,33(1):79-89.
APA	Kang, Y. H.,Yan, H.,Chen, R. S.,Yan, H,&Chen, RS .(2017).Creep Behavior and Microstructure Evolution of Sand-Cast Mg-4Y-2.3Nd-1Gd-0.6Zr Alloy Crept at 523-573 K.JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY,33(1),79-89.
MLA	Kang, Y. H.,et al."Creep Behavior and Microstructure Evolution of Sand-Cast Mg-4Y-2.3Nd-1Gd-0.6Zr Alloy Crept at 523-573 K".JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY 33.1(2017):79-89.