【作者】 谢勤；

【导师】 舒余德；

【作者基本信息】 中南大学 ， 冶金物理化学， 2001， 博士

【摘要】 传统的镀锌层，是防止钢铁腐蚀的应用最广泛最经济的措施。随着现代工业和科学技术的飞速发展，传统的镀锌层已不能满足要求。为此，人们采取了一系列措施，其中最有效的方法之一就是电镀锌基合金。具有耐蚀性高、延展性好、低氢脆、内应力小等优点的锌基合金镀层必将替代锌镀层、铬镀层和镉镀层，在汽车、造船、航空、建筑、交通设施和电子工业中得到广泛应用。在中国，锌基合金电镀技术尚处在研究开发阶段。因此，本文研究了弱酸性氯化物体系中Zn-Ni、Zn-Ni-P合金电镀工艺及其基础理论，以期缩短我国锌基合金电镀与世界水平间的差距。 本文采用浓硫酸对乳化剂OP-10进行硫酸化改性，确定了硫酸化工艺的最佳条件。以改性后的OP为载体光亮剂，复配适量的主光亮剂和辅助光亮剂，得到了浊点高、光亮电流密度区域宽的锌镍合金电镀添加剂。 研究了微酸性氯化物体系中电镀光亮Zn-Ni合金镀层和弱酸性简单氯化物体系中电镀Zn-Ni-P合金镀层的工艺，探讨了镀液各组分及工艺条件对合金镀层中Ni及磷含量的影响，得到了电镀Zn-Ni及Zn-Ni-P合金镀层的最佳镀液组成及工艺条件。分别考察了含镍13％的Zn-Ni及合镍15％、含磷0.9％的Zn-Ni-P合金镀层在5％NaCl溶液（30℃）中的耐蚀性能，它们的寿命是经过白色钝化同等厚度（8μm）的纯锌镀层的6～8倍。 采用非银盐、铜盐发黑剂，系统研究了锌镍合金镀层的黑色钝化工艺，并将磷化工艺结合进钝化中，得到了厚膜型钝化膜。经该黑色钝化工艺钝化的锌镍合金的耐腐蚀寿命是纯锌镀层的8～9倍。 采用线性电势扫描法研究Zn-Ni合金共沉积和Zn-Ni-P合金共沉积的电化学行为，讨论了镀液组成及温度对镀层耐蚀性的影响，发现了Zn-Ni-P合金电镀过程中Ni与P之间存在着协同效应。 用交流阻抗法研究了锌镍合金的腐蚀机理，并结合能带理论的费米能级概念和量子电化学理论，阐述了锌镍合金具有优异耐蚀性的根本原因。 利用各种电化学研究手段研究了Zn-Ni-P合金镀层中P的阴极析出机理，推导出P还原的反应动力学方程，求得各动力学参数，并运用该析出机理解释合金沉积过程中产生的镍与磷之间的协同效应。更多还原

【Abstract】 Zinc deposits have been widely used to protect steel from corrosion due to their low costs. However, the corrosion resistance of the zinc coatings can cope with automobile etc demands in company with the fast development of modem industry and technology, so, many methods have been proposed to improve the corrosion resistance of the zinc coatings. Among these, electrodeposited zinc alloys (such as zinc-nickel, zinc-iron, zinc-cobalt) have been found to possess various beneficial properties, include excellent corrosion resistance, good ductibility, low hydrogen embrittlement and small internal stress. Zn alloys are being considered as substitutes for zinc, cadmium and chromium plating widely used in automobile, aviation, shipbuilding, construction, means of transportation and electronic industry. In China, however; this new technique is virtually at a stage of lab research. This dissertation, based on current research, tries to study the electroplating process of weak acid chloride based Zn-Ni and Zn-Ni-P and the fundamentals, aiming to shorten the gap between China and the world concerning the zinc alloys electroplating technique.The main subjects of the dissertation are as follows:For the first time, oil of vitriol is used to sulfonate OP, and the optimum conditions of sulfonating reaction are ascertained. By making sulfonated OP as carrying agent brighter and co-operating with appropriate amount of main brighter and assistant brighter, a zinc alloy electroplating additive, which has a high turbidity point and wide brighter current density region, is obtained.The processes of Zn-Ni alloy electroplating from faintly acid chloride bath and Zn-Ni-P alloy electroplating from uncomplexed acid chloride bath have been studied. Through the analysis of the electrolyte ingredients, the process variables and their relationship with the Ni and/or P content in the coatings, the optimum processes have been obtained. The corrosion tests show that the corrosion resistance of the Zn-Ni coating with the content of I 3wt0/o Ni is six times as strong as that of the Zn coating of the same thickness with white chromate film, and the Zn-Ni-P coating with the content of 1 5wt% Ni and O.9wt% P is eight times as strong as that of the Zn coating.The optimum processes of fomiing a thick anticorrosive black chromate film on a Zn-Ni coating has been obtained. In this process, the phosphatization is incorporated to increase the thickness of the film, and the transition element salt is used as blacken agent to take the placeIIof soluble silver or cOPper salt. The Zn-Ni coating with the black chromate film is eigh to ninetimes as StrOng as tha of the Zn coating.The eleCtrOchendcal behaviors of the Zn-Ni electrolyte and the Zn-Ni-P eleCtrOlyte havebeen nded resPeCtively by linear POtential sweep method. It has been discovered that Niconient in the Zn-Ni coating is influenced by the comPOsihon of the electroIyte, by theadditives and by tempeha. It also has been discovered tha Ni and P in the An-Ni-P platingprocess show cooPefative effect.Qulck corrosive exPeriment weak polariZation and altemating cimnt hoPedance methodsare used to examind the excelleni cormsive resisate of Zn-Ni co8tirig. The mechtrisms ofthe cormsion of ZnNi and Zn coatings are studied by using altemaing cwrent impedancemethods and the theories of energy band theory and quantUm electrochemisnySevetal kinds of eleCtrchendcal methods are used tO explore the mechanism ofphosPhona incoopration during the electredeposihon of Znoui-P alloy The ldnatics equationsof the P reducing reaction are derived bom the mechbosm and the klnetic parameters areobtained bo the experiments. The cooPerative effect of Ni and P in the Zn-Ni-P platingprocess can be explained by the me-sm.更多还原