In vitro corrosion resistance of a Ta2O5 nanofilm on MAO coated magnesium alloy AZ31 by atomic layer deposition

Chang-Yang Li; Chi Yu; Rong-Chang Zeng; Bo-Cheng Zhang; Lan-Yue Cui; Jun Wan; Yang Xia

Bioactive Materials (Mar 2020)

In vitro corrosion resistance of a Ta2O5 nanofilm on MAO coated magnesium alloy AZ31 by atomic layer deposition

Chang-Yang Li,
Chi Yu,
Rong-Chang Zeng,
Bo-Cheng Zhang,
Lan-Yue Cui,
Jun Wan,
Yang Xia

Affiliations

Chang-Yang Li: Corrosion Laboratory for Light Metals, College of Materials Science and Engineering, Shandong University of Science and Technology, Qingdao, 266590, China
Chi Yu: Corrosion Laboratory for Light Metals, College of Materials Science and Engineering, Shandong University of Science and Technology, Qingdao, 266590, China
Rong-Chang Zeng: Corrosion Laboratory for Light Metals, College of Materials Science and Engineering, Shandong University of Science and Technology, Qingdao, 266590, China; School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450002, China; Corresponding author. College of Materials Science and Engineering, Shandong University of Science and Technology, Qingdao, 266590, China.
Bo-Cheng Zhang: Jiaxing Microelectronics Engineering Center, Chinese Academy of Sciences, Jiaxing, 314022, China; Corresponding author. Jiaxing Microelectronics Engineering Center, Chinese Academy of Sciences, Jiaxing, 314022, China.
Lan-Yue Cui: Corrosion Laboratory for Light Metals, College of Materials Science and Engineering, Shandong University of Science and Technology, Qingdao, 266590, China
Jun Wan: Jiaxing Microelectronics Engineering Center, Chinese Academy of Sciences, Jiaxing, 314022, China
Yang Xia: Institute of Microelectronics, Chinese Academy of Sciences, Beijing, 100029, China

Journal volume & issue: Vol. 5, no. 1
pp. 34 – 43

Abstract

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Micro-arc oxidation (MAO) coating with outstanding adhesion strength to Mg alloys has attracted more and more attention. However, owing to the porous structure, aggressive ions easily invaded the MAO/substrate interface through the through pores, limiting long-term corrosion resistance. Therefore, a dense and biocompatible tantalum oxide (Ta2O5) nanofilm was deposited on MAO coated Mg alloy AZ31 through atomic layer deposition (ALD) technique to seal the micropores and regulate the degradation rate. Surface micrography, chemical compositions and crystallographic structure were characterized using FE-SEM, EDS, XPS and XRD. The corrosion resistance of all samples was evaluated through electrochemical and hydrogen evolution tests. Results revealed that the Ta2O5 film mainly existed in the form of amorphousness. Moreover, uniform deposition of Ta2O5 film and effective sealing of micropores and microcracks in MAO coating were achieved. The current density (icorr) of the composite coating decreased three orders of magnitude than that of the substrate and MAO coating, improving corrosion resistance. Besides, the formation and corrosion resistance mechanisms of the composite coating were proposed. Keywords: Magnesium alloys, Micro-arc oxidation, Atomic layer deposition, Coatings

Published in Bioactive Materials

ISSN: 2452-199X (Online)
Publisher: KeAi Communications Co., Ltd.
Country of publisher: China
LCC subjects: Technology: Electrical engineering. Electronics. Nuclear engineering: Materials of engineering and construction. Mechanics of materials; Science: Biology (General)
Website: https://www.keaipublishing.com/en/journals/bioactive-materials/

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