电镀Ni-Sn镀层在人工汗液中的腐蚀行为

Corrosion Behavior of Ni-Sn Alloy in Artificial Sweat

采用环保络合剂体系制备Ni-Sn合金镀层。通过Tafel曲线测试、交流阻抗测试、扫描电镜、X射线衍射研究了Ni-Sn合金在人工汗液中的腐蚀行为。结果表明,镀态镀层为Ni相晶态结构,Ni-Sn合金镀层的耐腐蚀性随镀层中Sn含量的增加先升高后下降,Sn含量为8.88%的镀层在人工汗液中的耐蚀性最佳。交流阻抗测试及浸泡挂片实验结果与Tafel曲线测试结果一致。热处理实验表明,镀层耐腐蚀性能随热处理温度的升高先提高后降低,200℃热处理后镀层耐腐蚀性能最好,热处理温度高于400℃后镀层开始有新相Ni4Sn析出,镀层耐腐蚀性能随之降低。

The Ni-Sn alloy coating was prepared by using an environment-friendly complex system.The corrosion behavior of Ni-Sn alloy in artificial sweat was studied by Tafel curve test,AC impedance test,scanning electron microscopy and X-ray diffraction.The results show that the plated coating is a Niphase crystalline structure.The corrosion resistance of the Ni-Sn alloy coating firstly increases and then decreases with the increasing of Sn content in the coating.The corrosion resistance of the coating with the Sn content of 8.88%in artificial sweat achieves the best.The results of the AC impedance test and the immersion coupon test are consistent with the Tafel curve test.The heat treatment experiment shows that the corrosion resistance of the coating firstly increases and then decreases with the increasing of heat treatment temperature.The corrosion resistance of the coating is the best after heat treatment at 200℃.When the heat treatment temperature is higher than 400℃,a new phase Ni4Sn begins to precipitate and the corrosion resistance of the coating reduces.