添加剂对从无氰电解质中电沉积铜的协同效应及其结构和形貌特征

摘要

Electrodeposition of acid copper plating on mild steel substrate is tedious due to the galvanic displacement reaction of copper on mild steel.This can be avoided by using a proper complexing agent,because the complexing agent tuned the potential of noble direction to less noble direction by complex formation.In this paper,environment friendly electrodeposition of copper from non-cyanide electrolyte using sodium gluconate as complexing agent was investigated in alkaline medium.The effects of additives such as 1,2,3-benzotriazole,sodium lauryl sulphate,PEG 8000 and saccharin were studied.These additives are found to reduce the grain size,grain boundaries and improve surface morphology of the copper deposits.Also they improve the throwing power of the depositing electrolytes and hardness of deposits.The electrodeposited copper coatings were characterized by X-ray diffraction technique.XRD results indicate that the electrodeposited copper shows polycrystalline and face centered cubic structure.The crystal size was calculated by XRD and AFM analysis.Among these additives studied,the mixture of benzotriazole and sodium lauryl sulphate acts as the best additive.A uniform pore-free surface observed under SEM and AFM results reveal the grain refining brought about by the additives.%由于铜在低碳钢上的伽伐尼置换反应,酸性铜板在低碳钢基体上的电沉积比较困难.使用一种适宜的络合剂可解决这一问题,因为络合剂能通过形成配位化合物降低铜的电位.本文作者研究在碱性介质中以葡萄糖酸钠为络合剂从无氰电解质中电沉积铜.考察1,2,3-苯并三唑、十二烷基硫酸钠、聚乙二醇-800和糖精等添加剂对铜电沉积的影响.结果表明,这类添加剂不仅能降低电沉积铜的晶粒尺寸和晶界、改善其表面形貌,而且能提高电解质的均镀能力及电沉积铜的硬度.采用X射线衍射技术(XRD)对沉积铜进行表征.XRD结果表明,电沉积铜为多晶和面心立方结构.利用XRD结合原子力显微镜(AFM)计算电沉积铜的晶粒尺寸.在所研究的添加剂中苯并三唑和十二烷基酸钠混合添加剂的效果最好.用扫描电镜观察到的均匀无孔表面及AFM结果显示,上述添加剂能使电沉积铜的晶粒细化.