Composition and microstructure dependent corrosion behaviour of Mg-Li alloys

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	Composition and microstructure dependent corrosion behaviour of Mg-Li alloys
	Li, CQ; Xu, DK; Chen, XB; Wang, BJ; Wu, RZ; Han, EH; Birbilis, N; Birbilis, N (reprint author), Chinese Acad Sci, Inst Met Res, CAS Key Lab Nucl Mat & Safety Assessment, Shenyang 110016, Liaoning, Peoples R China.; Xu, DK (reprint author), Monash Univ, Dept Mat Sci & Engn, Clayton, Vic 3800, Australia.
刊名	ELECTROCHIMICA ACTA
	2018-01-10
卷号	260 页码:55-64
关键词	Magnesium Alloys Electrochemical Impedance Crystallographic Texture Mechanical Anisotropy Icosahedral Phase Al Composition Strength Spectroscopy Deformation Dissolution
ISSN号	0013-4686
英文摘要	The corrosion and electrochemical behaviour of carefully prepared ultra-lightweight magnesium-lithium (Mg-Li) alloys were investigated and compared. The alloy compositions studied were selected to provide the ability to compare unique microstructures and crystal structures, which arise from specific alloying additions of Li. Mg-4% Li is hexagonal closed-packed (HCP) alloy with Li in solid solution of Mg (alpha-Mg); Mg-14% Li is a fully solid solution BCC (beta-Li) alloy, whilst Mg-7.5% Li is a duplex (alpha-Mg thorn beta-Li) alloy. Testing in 0.1 M NaCl revealed that the corrosion performance and electrochemical response of the Mg-Li system evolved with the composition and crystallographic structure. For Mg-4% Li alloy, filiform-like corrosion morphology can be observed on the corroded surface, whilst a mixture of filiform-like corrosion to the alpha-Mg and localised dissolution of b-Li existed on the corroded surface of Mg-7.5% Li alloy. In the case of the BCC structured Mg-14% Li alloy, minor pitting was observed, concomitant with a generally low corrosion rate (particularly low corrosion rate for typical Mg alloys) and an increasing corrosion resistance with exposure time were also revealed. A combination of exposure testing inclusive of hydrogen collection and mass loss, in addition to potentiodynamic polarisation and impedance spectroscopy elucidated and quantified the corrosion performance of three differently structured Mg-Li alloys. It revealed that in spite of being composed of reactive elements of Mg and Li, the formation of beta-Li phases with BCC structure could facilitate the formation of a highly protective surface film which results in a predictable and consistently low corrosion rate of the Mg-14% Li alloy. (C) 2017 Elsevier Ltd. All rights reserved.; The corrosion and electrochemical behaviour of carefully prepared ultra-lightweight magnesium-lithium (Mg-Li) alloys were investigated and compared. The alloy compositions studied were selected to provide the ability to compare unique microstructures and crystal structures, which arise from specific alloying additions of Li. Mg-4% Li is hexagonal closed-packed (HCP) alloy with Li in solid solution of Mg (alpha-Mg); Mg-14% Li is a fully solid solution BCC (beta-Li) alloy, whilst Mg-7.5% Li is a duplex (alpha-Mg thorn beta-Li) alloy. Testing in 0.1 M NaCl revealed that the corrosion performance and electrochemical response of the Mg-Li system evolved with the composition and crystallographic structure. For Mg-4% Li alloy, filiform-like corrosion morphology can be observed on the corroded surface, whilst a mixture of filiform-like corrosion to the alpha-Mg and localised dissolution of b-Li existed on the corroded surface of Mg-7.5% Li alloy. In the case of the BCC structured Mg-14% Li alloy, minor pitting was observed, concomitant with a generally low corrosion rate (particularly low corrosion rate for typical Mg alloys) and an increasing corrosion resistance with exposure time were also revealed. A combination of exposure testing inclusive of hydrogen collection and mass loss, in addition to potentiodynamic polarisation and impedance spectroscopy elucidated and quantified the corrosion performance of three differently structured Mg-Li alloys. It revealed that in spite of being composed of reactive elements of Mg and Li, the formation of beta-Li phases with BCC structure could facilitate the formation of a highly protective surface film which results in a predictable and consistently low corrosion rate of the Mg-14% Li alloy. (C) 2017 Elsevier Ltd. All rights reserved.
学科主题	Electrochemistry
语种	英语
资助机构	National Key Research and Development Program of China [2017YFB0702001]; National Natural Science Foundation of China [51701129, 51271183, 51301172]; Strategic New Industry Development Special Foundation of Shenzhen [JCYJ20170306141749970]; National Basic Research Program of China (973 Program) [2013CB632205]; Innovation Fund of Institute of Metal Research (IMR), Chinese Academy of Sciences; China Scholarship Council; Australian Research Council [DP150103290]; Woodside Energy
公开日期	2018-06-05
内容类型	期刊论文
源URL	[http://ir.imr.ac.cn/handle/321006/79588]
专题	金属研究所_中国科学院金属研究所
通讯作者	Birbilis, N (reprint author), Chinese Acad Sci, Inst Met Res, CAS Key Lab Nucl Mat & Safety Assessment, Shenyang 110016, Liaoning, Peoples R China.; Xu, DK (reprint author), Monash Univ, Dept Mat Sci & Engn, Clayton, Vic 3800, Australia.
推荐引用方式 GB/T 7714	Li, CQ,Xu, DK,Chen, XB,et al. Composition and microstructure dependent corrosion behaviour of Mg-Li alloys[J]. ELECTROCHIMICA ACTA,2018,260:55-64.
APA	Li, CQ.,Xu, DK.,Chen, XB.,Wang, BJ.,Wu, RZ.,...&Xu, DK .(2018).Composition and microstructure dependent corrosion behaviour of Mg-Li alloys.ELECTROCHIMICA ACTA,260,55-64.
MLA	Li, CQ,et al."Composition and microstructure dependent corrosion behaviour of Mg-Li alloys".ELECTROCHIMICA ACTA 260(2018):55-64.