A single Ni coating and a Ni/Zn composite coating were prepared respectively on U-0.75Ti alloy surface by sulfamate nickel plating and cyanide-free alkaline zinc plating processes. The microstructures and morphologies of the coatings were characterized by optical microscopy and scanning electron microscopy. Their corrosion resistance were studied by weighing method, accelerated damp heat corrosion testing and open circuit potential measurement. The results showed that Zn coating is an anodic coating to U-0.75Ti alloy while Ni coating is a cathodic one. The total thickness of the Ni and Zn coatings prepared was about 37μm, and its corrosion rate is lower than that of the single Ni coating in both 50μg/g Cl? aqueous solution and 70 °C/80％RH environment, indicating that the Ni/Zn composite coating has a good protection to U-0.75Ti alloy.%采用氨基磺酸盐镀镍液和无氰碱性镀锌液在U-0.75Ti铀钛合金表面制备了单一Ni镀层和Ni/Zn复合镀层.利用光学显微镜和扫描电子显微镜对镀层的组织形貌进行了表征.通过失重法、湿热加速腐蚀试验和开路电位测量,对镀层的耐蚀性能进行了考察.结果表明:对于U-0.75Ti合金而言,Zn镀层是阳极性保护镀层,而Ni镀层阴极性保护镀层;Ni/Zn复合镀层的总厚度约为37μm.在含50μg/g Cl?的水溶液及70°C、相对湿度80％的湿热环境中,Ni/Zn复合镀层的腐蚀速率比单一Ni镀层低,对U-0.75Ti合金基体起到了良好的保护作用.
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