Corrosion resistance of in-situ growth of nano-sized Mg（OH）2 on micro-arc oxidized magnesium alloy AZ31—Influence of EDTA

作     者：Chang-Yang Li Xiao-Li Fan Rong-Chang Zeng Lan-Yue Cui Shuo-Qi Li Fen Zhang Qing-Kun He M. Bobby Kannan Hong-Wei (George) Jiang Dong-Chu Chen Shao-Kang Guan 

作者机构：College of Materials Science and Engineering Shandong University of Science and Technology Qingdao 266590 China Biomaterials and Engineering Materials (BEM) Laboratory College of Science Technology and Engineering James Cook University Townsville 4811Australia School of Engineering RMIT University Carlton 3053 VIC Australia School of Materials Science and Energy Engineering Foshan University Foshan 528000 China School of Materials Science and Engineering Zhengzhou University Zhengzhou 450002 China 

出 版 物：《Journal of Materials Science & Technology》 (材料科学技术（英文版）)

年 卷 期：2019年第35卷第6期

页      面：1088-1098页

核心收录：

学科分类：08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：supported by the National Natural Science Foundation of China(Nos.51571134 and 51601108) the SDUST Research Fund(No.2014TDJH104) 

主　　题：Magnesium alloys Micro-arc oxidation Magnesium hydroxide Coatings Biomaterials 

摘      要：One of the major obstacles for the clinical use of biodegradable magnesium(Mg)-based materials is their high corrosion rate. Micro-arc oxidation(MAO) coatings on Mg alloys provide mild corrosion protection owing to their porous structure. Hence, in this study a dense Mg(OH)2 film was fabricated on MAO-coated Mg alloy AZ31 in an alkaline electrolyte containing ethylenediamine tetraacetic acid disodium(EDTA-2 Na) to reinforce the protection. Surface morphology, chemical composition and growth process of the MAO/Mg(OH)2 hybrid coating were examined using field-emission scanning electron microscopy, energy dispersive X-ray spectrometer, X-ray diffraction, X-ray photoelectron spectroscopy and Fourier transform infrared spectrophotometer. Corrosion resistance of the coatings was evaluated via potentiodynamic polarization curves and hydrogen evolution tests. Results manifested that the Mg(OH)2 coating possesses a porous nano-sized structure and completely seals the micro-pores and micro-cracks of the MAO *** intermetallic compound of AlMn phase in the substrate plays a key role in the growth of Mg(OH)2 film. The current density of Mg(OH)2-MAO composite coating decreases three orders of magnitude in comparison with that of bare substrate, indicating excellent corrosion resistance. The Mg(OH)2-MAO composite coating is beneficial to the formation of calcium phosphate corrosion products on the surface of Mg alloy AZ31, demonstrating a great promise for orthopaedic applications.