Effects of pH and temperature on the deposition properties of stannate chemical conversion coatings formed by the potentiostatic technique on AZ91 D magnesium alloy
Effects of pH and temperature on the deposition properties of stannate chemical conversion coatings formed by the potentiostatic technique on AZ91 D magnesium alloy
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DOI：
10.1016/j.electacta.2008.01.009
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发表时间：
2008-05
影响因子：
6.6
通讯作者：
Hassan H. Elsentriecy;K. Azumi;H. Konno
中科院分区：
文献类型：
--
作者：
Hassan H. Elsentriecy;K. Azumi;H. Konno
为了提高镀膜的均匀性和防腐性能，研究了锡酸盐镀液的pH和温度对E= - 1.1V恒电位极化技术在az91d镁合金上形成锡酸盐化学转化膜质量的影响。结果表明，恒电位极化镀膜的均匀性和耐蚀性与镀液的pH和温度密切相关。通过硼酸盐缓冲溶液的动电位阳极极化曲线，研究了最佳涂膜的pH和温度与防腐性能的关系。扫描电镜观察和电化学腐蚀试验证实，通过改变镀液的pH值和温度，恒电位法沉积的镀锡膜的均匀性和耐蚀性得到了显著改善。在最佳的镀液pH和温度条件下，采用恒电位法沉积的镀层的均匀性和耐蚀性都明显优于单纯浸没法沉积的镀层。
The effects of pH and temperature of a stannate bath on the quality of stannate chemical conversion coatings formed on AZ91 D magnesium alloy by using the potentiostatic polarization technique at E=−1.1V were investigated in order to improve uniformity and corrosion protection performance of the coating films. It was found that the uniformity and corrosion resistance of coating films deposited by potentiostatic polarization were closely associated with pH and temperature of the coating bath. The pH and temperature to obtain the best coating film were investigated as a function of corrosion protection performance evaluated by curves of potentiodynamic anodic polarization conducted in borate buffer solution. Scanning electron microscope observation and electrochemical corrosion tests of the stannate-coated samples confirmed significant improvement in uniformity and corrosion resistivity of coating films deposited by the potentiostatic technique by modifying the pH and temperature of the coating bath. It was also found that uniformity and corrosion resistivity of the coating films deposited by the potentiostatic technique were considerably improved compared to those of coatings deposited by the simple immersion method at the best conditions of pH and temperature of the coating bath.