Mechanistic study of ammonium-induced corrosion of AZ31 magnesium alloy in sulfate solution
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2020年第19期
论文作者：Hui Pan Liwei Wang Yi Lin Feng Ge Kang Zhao Xin Wang Zhongyu Cui
文章页码：1 - 13
摘 要：The influence of NH4+ ions on the corrosion behavior of AZ31 magnesium alloy was investigated by immersion test, hydrogen evolution, electrochemical methods and morphology observation. The results demonstrate the acceleration effect of NH4+ on corrosion of AZ31 magnesium alloy due to the disruption of protective Mg O film in NH4+-containing solution. The loose and cracked corrosion products of AZ31 magnesium alloy in NH4+-containing solutions are mainly composed of(Mg0.833Al0.167)（OH）2（CO3）0.083·0.75 H2O and Mg5（CO3）4（OH）2·5 H2O. When the NH4+concentration is lower than 0.01 M, knife-cut like corrosion occurs in some active area of the surface due to the partial dissolution of Mg O layer. As the NH4+concentration is increased to 0.1 M, the Mg O layer is completely disrupted, resulting in the occurrence of uniform corrosion. Both cathodic and anodic reactions are accelerated by NH4+ions, while the effect of original pH values on the reaction kinetics can be neglected in NH4+-containing solutions.
Hui Pan1，Liwei Wang2，Yi Lin1，Feng Ge1，Kang Zhao2，Xin Wang1，Zhongyu Cui1
1. School of Materials Science and Engineering, Ocean University of China2. College of Electromechanical Engineering, Qingdao University
摘 要：The influence of NH4+ ions on the corrosion behavior of AZ31 magnesium alloy was investigated by immersion test, hydrogen evolution, electrochemical methods and morphology observation. The results demonstrate the acceleration effect of NH4+ on corrosion of AZ31 magnesium alloy due to the disruption of protective Mg O film in NH4+-containing solution. The loose and cracked corrosion products of AZ31 magnesium alloy in NH4+-containing solutions are mainly composed of(Mg0.833Al0.167)（OH）2（CO3）0.083·0.75 H2O and Mg5（CO3）4（OH）2·5 H2O. When the NH4+concentration is lower than 0.01 M, knife-cut like corrosion occurs in some active area of the surface due to the partial dissolution of Mg O layer. As the NH4+concentration is increased to 0.1 M, the Mg O layer is completely disrupted, resulting in the occurrence of uniform corrosion. Both cathodic and anodic reactions are accelerated by NH4+ions, while the effect of original pH values on the reaction kinetics can be neglected in NH4+-containing solutions.
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