基于阳离子型聚丙烯酰胺高聚物溶液的电化学沉积试验研究

以阳离子型聚丙烯酰胺(CPAM)高聚物为唯一添加剂,采用直流电源在超低电压下开展锌镀层电化学沉积试验,重点研究了CPAM离子度对锌镀层表面形貌、成分和电流密度的影响,考察了主盐Zn2+和CPAM的质量浓度对镀层微观形貌、晶粒平均直径的影响规律。结果表明:离子度20%的CPAM-ZnSO4高聚物溶液在0.3 V超低电压下获得的沉积层致密、晶粒尺寸均匀、表面平整光亮且电流密度达0.47 A/dm2;随着Zn2+和CPAM的质量浓度增加,镀层中锌含量增多,沉积层表面形貌由圆形颗粒变为片状晶体且表面晶粒细化;当Zn2+质量浓度40 g/L、CPAM质量浓度20 g/L、电压0.3 V时,电沉积5 min时,可制备出表面光亮、晶粒平均直径87 nm的镀锌层。

Experimental Research on Electrochemical Deposition Based on Cationic Polyacrylamide Polymer Working Fluid

Cationic polyacrylamide(CPAM)high polymer was used as the only additive,and the electrochemical deposition experiment of zinc coating was carried out under ultra-low voltage using DC power supply.The influence of CPAM ion degree on the surface morphology,composition and current density of zinc coatings was explored.The influence of main salt Zn2+mass concentration and CPAM mass concentration on the coating micromorphology and average grain diameter was investigated.The results show that CPAM-ZnSO4 polymer solution with 20%ion degree,under 0.3 V ultra-low voltage,the deposited layer is dense,the grain size is uniform,the surface is smooth and bright,and the current density can reach 0.47 A/dm2.In addition,as the mass concentration of Zn2+and CPAM in the polymer solution increases,the zinc content in the coating increases,and the surface morphology of the deposition layer changes from round particles to flaky crystals,and the surface grains are refined.When the mass concentratio of Zn2+is 40 g/L,the mass concentration of CPAM is 20 g/L,and the voltage is0.3 V,a galvanized layer with bright surface and an average crystal grain diameter of 87 nm can be prepared by electrodeposition for 5 min.