γ相Zn-Ni合金镀层结构及性能分析

Structure and Performance Analysis of Zn-Ni Alloy Coating with γ phase

采用电沉积方法从碱性镀液中制备γ相Zn-Ni合金镀层,应用扫描电子显微镜、X-射线衍射仪、电化学测量技术对Zn-Ni合金镀层的微观结构和耐蚀性能进行了研究。结果表明,Ni-Zn合金镀层的腐蚀性与其微结构密切相关。Zn-Ni合金镀层的晶型为γ相,合金镀层中镍和锌的质量分数分别为15.98%和84.02%;锌-镍合金镀层中原子堆积方式为正四面体形。在5%氯化钠溶液中,γ相Zn-Ni合金镀层与锌镀层的电化学测试结果表明,在0-10Hz低频率区,γ-相Zn-Ni合金镀层的交流阻抗谱的实部值为镀锌层的7.2倍;腐蚀电位比锌层增加了0.1279V,镀锌层的Jcorr是γ相Zn-Ni合金镀层的5.78倍。

Zn-Ni alloy coating with γ phase was prepared by electrodeposition in alkaline electrolyte.Scanning electron microscopy,X-ray diffraction spectroscopy and electrochemical measurement were applied to investigate the microstructure and corrosion resistance of prepared Zn-Ni alloy coating and zinc coating.Results showed that the corrosion resistance of Zn-Ni alloy coating was closely related with its intrinsic microstructures.The prepared Zn-Ni alloy was identified as in γ phase with the structure of regular tetrahedron and the mass content of 15.96％ Ni and 84.02％ Zn.The electrochemical test results of ZnNi coating and zinc coating in 5％ NaC1 solution indicated that the electrochemical impedance of Zn-Ni coating was 7.2 times than that of zinc coating,and the corrosion potential of Zn-Ni coating was positively shift 0.1279V to zinc coating.But the corrosion current density of Zn coating was 5.78 times than that of Zn-Ni coating.