二元配合物中电镀锌镍合金的结构与抗腐蚀性

为深入了解碱性锌酸盐体系的工艺参数对锌镍合金镀层结构和耐蚀性的影响,在以四乙烯五胺(TEPA)为镍离子主络合剂、三乙醇胺(TEA)为辅助络合剂的碱性镀液中电沉积制备了锌镍合金镀层,利用电子能谱、X射线衍射、极化曲线和电化学阻抗谱等方法表征镀层的组成结构和在氯化钠溶液中的耐腐蚀性.结果表明:镀层含镍原子数分数11.54%～20.12%,为γ-Ni2Zn11+纯Zn两相结构(低含镍原子数分数时)或单一γ相结构(较高含镍原子数分数时),γ相晶粒在(600)方向上具有不同程度的择优取向性；随着镀液中镍原子数分数的提高,镀层的腐蚀电位正移,阻抗增加,耐蚀性提高；当电流密度为2 A/dm2时,镀层的腐蚀电位和电荷传递电阻最高,耐蚀性最好.
To know how the technological parameters affect the structure and anti-corrosion property of Zinc-nickel alloy plating in alkaline zincate system, the synthesis of the zinc-nickel alloy plating is made by the electrochemical deposition method. The alkaline solution is a mixture of Tetraethylenepentamine (TEPA) and Triethanolamine (TEA), and the prior part is the main complexing agent for nickel ions. The energy dispersive spectrometer (EDS), X-ray diffraction (XRD) associated with polarization curves and electrochemical impedance spectroscopy (EIS) were used to characterize the structure and anti-corrosion property respectively. The result shows that the particles in γ-phase preferred (600) orientation with respect to the atom percentage of nickel varies between 11.54% and 20.12%, 11.54% corresponds to a γ-Ni2Zn11 and Zn two-phase area and 20.12% corresponds to a single γ-phase. With an increasing atom percentage of nickel in the bath, the corrosion potential of plating becomes more positive, which results in an increasing impedance and a better anti-corrosion property. At last, the plating displays its highest corrosion resistance when the current density reaches 2 A/dm2.