锌-铁合金异常共沉积中锌沉积机理的研究(Ⅰ)——Zn阴极沉积反应历程的拟定  

Depositing Mechanism of Zn in Zn-Fe Alloy Anonymous Codeposition (I)——Cathodic Reaction Course of Zn Deposition

作　　者：王云燕[1] 彭文杰[1] 

机构地区：[1]中南大学冶金科学与工程学院,湖南长沙410083

出　　处：《材料保护》2004年第11期1-4,共4页Materials Protection

摘　　要：　为确定Zn-Fe合金异常共沉积过程中Zn的沉积机理,在机理研究的合理假设条件下,运用各种电化学测试方法研究了Zn-Fe合金异常共沉积中Zn的阴极沉积性质,将理论推导与试验数据相结合拟定出了电极反应历程。碱性锌酸盐电镀液中(pH>13)锌离子主要是以四配位体Zn(OH)2-4的形式存在;电极反应活化能为38.93kJ/mol,表明Zn(OH)2-4在阴极放电受电化学极化控制,Zn(OH)2-4在阴极放电首先经历前置化学转化反应,放电分两步进行,Zn(OH)2-4的扩散系数为2.452×10-6cm2/s。体系中直接放电的配离子为Zn(OH)2。Cathodic depositing behaviors of zinc were investigated to confirm the deposition mechanism of Zn-Fe alloy anonymous codeposition by using kinds of electrochemical techniques under the reasonable assumption. Combining the theoretical deduction and experimental resuls, the electrode reaction course was studied out. Zinc ions mainly exist in the form of Zn(OH)^(2-)_4 in the alkaline zincate bath (pH>13). The activation energy of electrode reaction is 38.93 kJ/mol, which indicates that the discharge of Zn(OH)^(2-)_4 on cathode is controlled by electrochemical polarization. The discharge of Zn(OH)^(2-)_4 on cathode firstly goes through the preceding chemical transfer reaction. Zn(OH)^(2-)_4 receives two electrons on cathode step by step. The diffusion coefficient of Zn (OH)^(2-)_4 is 2.452×10~6cm^2/s. The directly discharged ion in the system is Zn(OH)_2.

关 键 词：ZN-FE合金电镀 异常共沉积 Zn沉积机理 

分 类 号：TQ153.2[化学工程—电化学工业]