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

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

机构地区：[1]Corrosion Laboratory for Light Metals,College of Materials Science and Engineering,Shandong University of Science and Technology,Qingdao,266590,China [2]Jiaxing Microelectronics Engineering Center,Chinese Academy of Sciences,Jiaxing,314022,China [3]Institute of Microelectronics,Chinese Academy of Sciences,Beijing,100029,China [4]School of Materials Science and Engineering,Zhengzhou University,Zhengzhou,450002,China

出　　处：《Bioactive Materials》2020年第1期34-43,共10页生物活性材料（英文）

基　　金：This work was supported by the National Natural Science Foundation of China(51571134 and 51601108);the SDUST Research Fund(2014TDJH104).

摘　　要：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.

关 键 词：Magnesium alloys Micro-arc oxidation Atomic layer deposition Coatings 

分 类 号：TG146.22[一般工业技术—材料科学与工程] TB383[金属学及工艺—金属材料]