酸性化学镀镍磷合金的动力学机理

通过极化曲线研究了3种不同溶液（阴极液、阳极液和完整镀液）的电化学行为，测定了主盐、还原剂浓度以及镀液pH和体系温度对化学镀镍沉积速率的影响. 与直接在镁合金上化学镀镍并使用重量分析法得到的沉积速率相比较发现，完整镀液体系的极化曲线才能真实地反映化学镀镍的沉积过程，其过程不能简单视为由彼此完全独立毫无关联的阴阳极半反应构成. 根据Butler-Volmer公式，本化学镀液体系的化学镀镍过程属混合控制，其表观反应活化能为42.89 kJ·mol^-1.

Kinetics and Mechanism of Acidic Electroless Ni-P Plating

Electrochemical behaviors of electroless nickel (EN) plating in three systems, namely, cathodic, anodic and complete bath solutions were investigated by polarization methods. The curves in the complete baths were not entirely consistent with those expected from a combination of the anodic and cathodic polarization curves, which implies that the anodic and cathodic reactions of the EN plating are interdependent. The effects of concentration of nickel ions, hypophosphite and pH on the polarization parameter and deposition rate in a complete bath were also discussed and compared by performing electrochemical and gravimetrical measurements. Based on these variations in the deposition potential and current density, a kinetic expression employing the Butler-Volmer equation is suggested and verified with the experimental findings. It was confirmed that the electroless nickel deposition processes in the present system was under a mixed control. The apparent activation energy determined by electrochemical methods was about 42.89 kJ·mol^-1.