Potentiostatic Conversion of Phosphate Mineral Coating on AZ31 Magnesium Alloy in 0.1 M K2HPO4 Solution

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	Potentiostatic Conversion of Phosphate Mineral Coating on AZ31 Magnesium Alloy in 0.1 M K2HPO4 Solution
	L. P. Wu; L. Zhao; J. H. Dong; W. Ke; N. Chen
	2014
发表期刊	Electrochimica Acta
ISSN	0013-4686
卷号	145 页码:71-80
摘要	The coating process of a four layered phosphate mineral conversion coating on AZ31 Mg alloy deposited at -0.8 V in 0.1 M K2HPO4 solution with pH 9.5 was studied by in situ potentiostatic polarization, together with scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermal gravimetry (TG), differential scanning calorimetry (DSC), differential thermal gravimetry (DTG) and electron probe micro-analyzer (EPMA). Our results show that the coating process can be divided into five stages. The initial two stages are caused by the rapid decrease of charging current of the electrical double layer capacitance and the slow increase of faraday current density on AZ31 Mg alloy, and Mg(OH)(2) was detected in the corrosion product in these two stages. The third process corresponds to the deposition of amorphous MgHPO4 film, followed by the fourth process corresponding to the decrease of the corrosion resistance of MgHPO4. In the last stage, crystallized KMgPO4 center dot 6H(2)O (struvite-K) forms. The SEM, XPS, TG, DSC, DTG and EPMA indicate that the deposited coating consists of four layers. The innermost layer is composed of a corosion product, Mg(OH)(2), followed by the inner layer composed of Mg(OH)(2) and MgHPO4, subsequently the middle layer consisting of Mg(OH)(2), MgHPO4 and struvite-K, and finally the topmost layer consisting of MgHPO4 and struvite-K. (C) 2014 Elsevier Ltd. All rights reserved.
部门归属	[wu, liping ; zhao, lin ; dong, junhua ; ke, wei ; chen, nan] chinese acad sci, inst met res, environm corros ctr, shenyang 110016, peoples r china. ; dong, jh (reprint author), chinese acad sci, inst met res, environm corros ctr, shenyang 110016, peoples r china. ; jhdong@imr.ac.cn
关键词	az31?magnesium Alloy Phosphate Mineral Conversion Coating Struvite-k Potentiostatic Technique Coating Process Biodegradable Magnesium Corrosion-resistance Degradation Behavior Surface Modification Bone Struvite Electrodeposition Hydroxyapatite Nucleation Deposition
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语种	英语
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/73444
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	L. P. Wu,L. Zhao,J. H. Dong,et al. Potentiostatic Conversion of Phosphate Mineral Coating on AZ31 Magnesium Alloy in 0.1 M K2HPO4 Solution[J]. Electrochimica Acta,2014,145:71-80.
APA	L. P. Wu,L. Zhao,J. H. Dong,W. Ke,&N. Chen.(2014).Potentiostatic Conversion of Phosphate Mineral Coating on AZ31 Magnesium Alloy in 0.1 M K2HPO4 Solution.Electrochimica Acta,145,71-80.
MLA	L. P. Wu,et al."Potentiostatic Conversion of Phosphate Mineral Coating on AZ31 Magnesium Alloy in 0.1 M K2HPO4 Solution".Electrochimica Acta 145(2014):71-80.