【作者】 张长科；

【导师】 何凤姣；

【作者基本信息】 湖南大学 ， 分析化学， 2010， 硕士

【摘要】 铬镀层作为防护性和装饰性镀层在工业和生活中有着广泛的应用,但是金属铬的对人体和环境的危害性也早已经引起了人们的关注,作为代铬镀层而开发的钨合金镀层以其各方面优异的性能吸引了研究者广泛关注,如装饰性外观、高硬度、高耐磨性、高热稳定性、良好的耐蚀性。钨合金排除了有毒有害元素铬,并且采用绿色的柠檬酸做为络合剂,在生产过程中不会产生对环境有危害的废气和废水,属于绿色环保电镀工艺。钨合金在石油机械工业中已经取得了重要广泛的应用,随着钨合金技术的进一步完善,其将会在工业和生活中发挥越来越重要的作用。本文研究了不同钨含量Fe-Ni-W合金的耐腐蚀性能,并且在调整不同镍铁比的过程中发现,在钨合会中Fe、Ni呈现正常共沉积行为,鉴于此发现,详细研究了在碱性条件下电沉积Fe-Ni合金,并讨论了其可能的电沉积机理。本论文在以下几个方面开展了研究工作：(1)通过调整镀液组分得到了不同钨含量的Fe-Ni-W合金,并对其结构、表观形貌进行了表征,并通过动电位阳极极化曲线和电化学阻抗谱技术在3.5％NaCl溶液中对其耐腐蚀性能进行了详细的研究。(2)在碱性条件下,研究了分别采用氨水和氢氧化钠调节pH值的电解液中Fe-Ni合金电沉积行为,发现了铁镍合金的正常共沉积行为,并对其电化学特性进行了研究。(3)利用所得的实验数据及已有的电镀理论,提出了铁镍正常共沉积的反应机理。更多还原

【Abstract】 Chromium plating is used widely in industry and life as protective and decorative coating,however the toxicity of hexavalent chromium for human body and entironment had drew the attention of pepole.Tungsten alloy empoldered as the substitute of chromium plating had drew wide interest of researchers for decades by the excelent properties,i.e.decorative appearance,high rigidity,high wear Resistance,high thermal Stability and good corrosion resistence.Tungsten alloy get rid of the deleterious element Cr and use citric acid as complex agent.There are no harmful rejectamenta in the production process,so ti is Green Manufacturing Process. Tungsten alloy had already obtained very successful application in heavy machinery industry of petroleum.Tungsten alloy will play a more and more important role in industry and life in future along with the maturity of the technology.In this paper corrosion resistence of Fe-Ni-W alloy with different tungsten content in 3.5wt% NaCl solution was studied.We found that Fe and Ni element codeposition don’t obey the anomalous codeposition rule of iron groups metals.For this interesting discovery. We studied the codeposition of Fe-Ni alloy in detail under alkaline condition and discussed the possible mechanism.(1) We obtained Fe-Ni-W alloy coating by changing the content of electrolyte and technical parameters and characterized the surface morphology, structure. Corrosion behavior was investigated by electrochemical and gravimetric tests in 3.5 wt.% NaCl solution at 25℃(2) Under alkaline condition,the codeposition of Fe-Ni alloy was studied in electrolytes adjusted pH by NH3H2O or NaOH respectively.The regular codeposition of Fe-Ni alloy was discoved and studied the electrochemical characteristic.(3)The codeposition mechanism of Fe-Ni alloy was proposed according to the experiment datas and theoretics of electroplating.更多还原