Corrosion control of Cu-Ni alloys in neutral chloride solutions by amino acids
Corrosion control of Cu-Ni alloys in neutral chloride solutions by amino acids
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DOI：
10.1016/j.electacta.2005.11.037
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发表时间：
2006-05-25
影响因子：
6.6
通讯作者：
Fathi, Ahlam M.
中科院分区：
文献类型：
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作者：
Badawy, Waheed A.;Ismail, Khaled M.;Fathi, Ahlam M.
研究了氨基酸作为环境安全材料对Cu-Ni合金在氯化物溶液中的缓蚀作用。使用极化和阻抗技术计算在不存在和存在腐蚀抑制剂的情况下的腐蚀速率。实验结果表明，甘氨酸等简单氨基酸对Cu-Ni合金在中性氯化物溶液中具有良好的缓蚀效果。在非常低浓度的氨基酸（0.1mM）下可以实现约85%的抑制效率。对于低Ni含量的合金（Cu-5 Ni），2.0mM半胱氨酸显示出显著高（类似于96%）的腐蚀抑制效率。根据电极/电解质界面的等效电路模型，将实验阻抗数据与理论数据进行了拟合，并提出了缓蚀过程的机理。不同的吸附等温线进行了测试和缓蚀过程中发现，依赖于吸附的氨基酸分子和/或腐蚀产物在合金表面上的沉积。半胱氨酸在Cu-5 Ni上的吸附自由能为-37.81kJmol（-1），表明半胱氨酸在Cu-5 Ni上有较强的物理吸附。(c)2006爱思唯尔有限公司保留所有权利。
The corrosion inhibition of Cu-Ni alloys was investigated in aqueous chloride solutions using amino acids as environmentally safe materials. The corrosion rate was calculated in absence and presence of the corrosion inhibitor using polarization and impedance techniques. The inhibition efficiency of the different amino acids was also calculated.The experimental results have shown that a simple amino acid like glycine can be used as efficient corrosion inhibitor for the Cu-Ni alloys in neutral chloride solutions. An inhibition efficiency of about 85% could be achieved at very low concentrations of the amino acid (0.1 mM). For low Ni content alloy (Cu-5Ni), 2.0 mM cysteine shows a remarkable high (similar to 96%) corrosion inhibition efficiency. The experimental impedance data were fitted to theoretical data according to a proposed equivalent circuit model for the electrode/electrolyte interface, and the mechanism of the corrosion inhibition process was suggested. Different adsorption isotherms were tested and the corrosion inhibition process was found to depend on the adsorption of the amino acid molecules and/or the deposition of corrosion products on the alloy surface. The adsorption free energy of cysteine on Cu-5Ni (-37.81 kJ mol(-1)) reveals a strong physical adsorption of the inhibitor on the alloy surface. (c) 2006 Elsevier Ltd. All rights reserved.