电位活化现象与金属电沉积初始过程的研究

Study of Potential Activation Phenomenon and Initial Process of the Metal Electrodeposition

进行了恒电流电位-时间曲线和循环伏安曲线的测定,显示了铁电极进行氰化物镀铜时,镀层沉积前铁表面的电位活化过程.对铁电极上焦磷酸盐镀铜的初始过程研究表明,由于铜的析出电位较正,铜是在未活化的电极表面上沉积的,因此镀层的结合强度很差.采用氩离子溅射和X射线光电子能谱相结合的方法,检测焦磷酸盐镀铜层和铁基体界面区含氧量的变化,证明了氧化层的存在.通过添加辅助络合剂和控制起始电流密度的方法,可以增强无氰电镀时阴极的极化.当铜的析出电位负于铁基体的活化电位时,可显示出铁表面的电位活化过程,定量测量镀层的结合强度也与氰化物电镀相近.

The potential-time curves under constant current and cyclic voltammetry curves were measured, and the potential activation process of copper plating on iron substrate in cyanide electrolyte was shown. The initial process of pyrophosphate copper plating on the iron electrode was studied. The results show that deposition potential of copper is positive and copper deposits on the inactive surface of electrode. The bond intensity of plating layer is very bad. By using Ar ion sputtering and X-ray photoelectron spectroscopy, the oxygen contents between the copper plating layer and iron substrate were examined and the existence of oxygen layer was proved. Through adding assistant complexing agent and controlling initial current density, cathodic polarization was intensified in cyanide-free electrolyte. When the deposition potential of copper is less than activation potential of the iron substrate, the potential activation process was shown. The bond intensity of the plating layer is close to that of cyanide copper plating.