Characterization and wear resistance of macro-arc oxidation coating on magnesium alloy AZ91 in simulated body fluids

来源期刊：中国有色金属学报(英文版)2008年增刊第1期

论文作者：陈君 曾荣昌 黄伟九 郑自芹 王振林 王俊

文章页码：361 - 364

Key words：magnesium alloy; macro-arc oxidation; coating; erosion corrosion; biomaterial; simulated body fluid

Abstract: The mechanical characteristics of the macro-arc oxidation (MAO) coating on Mg alloy AZ91 were examined by means of nano scratch tester. The corrosion and erosion corrosion behavior of AZ91 with and without MAO coating were investigated by using potentiodynamic electrochemical technique and micro-abrasion tribometer in simulated body fluids, respectively. The influence of HCO₃^- ions on the erosion corrosion was discussed. The results show that the coating and its substrate are in a pronounced bond. The MAO coating increases 1-2 orders of magnitude of the corrosion resistance of AZ91 alloy. HCO₃^- ions enhance the corrosion rates of the AZ91 alloys more significantly than the alloys with MAO coating. However, there exists an obvious passivation process of AZ91 without coating in the HCO₃^- solutions. Moreover, an MgCO₃ film formed in HCO₃^- containing solutions leads to an enhancement in micro-wear resistance. MAO coating deteriorates the erosion corrosion resistance of AZ91 alloy due to the formation of oxidation debris resulted from the broken MAO coating.

基金信息：the National Natural Science Foundation of China
he New Century Excellent Talents in University, China
the Natural Science Foundation of Chongqing Science and Technology Commission, China