含芳香醛和含硫化合物的添加剂对无氰电镀银的影响  

Influence of Additive Containing Aromatic Aldehyde and Sulfur Compound on the Cyanide-Free Electroplating of Silver Coating

作　　者：单颖会[1] 于锦[1] 谭宏宇[1] 王丽丽[1] 

机构地区：[1]沈阳工业大学理学院,辽宁沈阳110123

出　　处：《材料保护》2011年第3期36-38,89-90,共3页Materials Protection

摘　　要：针对目前无氰镀银层外观差、附着力不良、镀液稳定性差等问题,采用横向划痕法、直角阴极法、赫尔槽8点法、阴极极化曲线及称重法对无氰电镀银的基础液和含添加剂SGD-DY1(芳香醛、含硫化合物和表面活性剂)的镀液进行了测试;用扫描电镜和XRD对镀层表面形貌和晶体结构进行了表征,用盐雾试验、耐3.0 mg/L H2S和0.1 mol/L K2SO4试验测试了镀层耐蚀性能和抗硫化变色性能。结果表明:由于SGD-DY1的加入,横向划痕完全消失,整平能力提高;深镀能力由原来的96%提高到100%,均镀能力由60%提高到80%;阴极极化曲线明显负移,阴极极化能力提高,阴极电流效率由96%下降到92%,镀层的沉积速度由12μm/h下降到10μm/h;镀层由(111)和(110)晶面择优取向向(111)晶面转变且镀层平整、晶粒细致;镀层的耐蚀性和抗变色性明显提高。Composite additive SGD-DY1 composed of aromatic aldehyde,S-containing compound and surfactant was introduced in cyanide-free electroplating bath to prepare Ag coating.The plating bath was analyzed using transverse scratch method,orthogonal cathode method,8-point method in Hull cell,cathode polarization method and weighing method.The morphology and crystal structure of the coating were analyzed by means of scanning electron microscopy and X-ray diffraction.The corrosion resistance of the coating was evaluated using salt spray test,and its resistance against vulcanization and tarnishing in aqueous solutions of 3.0 mg/L H2S and 0.1 mol/L K2SO4 was also evaluated.It was found that the introduction of SGD-DY1 contributed to removal of transverse scratches and improvement of leveling power,accompanied by increase of covering power from 96% to 100% and throwing power from 60% to 80%.The cathodic polarization curve was obviously shifted towards negative side along with the introduction of SGD-DY1,accompanied by increase of cathodic polarization ability.However,the cathodic current efficiency was reduced from 96% to 92%,and the deposition rate of the Ag coating was reduced from 12 μm/h to 10 μm/h.Moreover,adding SGD-DY1 resulted in transformation of preferential orientation of the coating from(110) plane to(111) plane and significant increase of corrosion resistance and anti-tarnishing ability of the coating.

关 键 词：无氰电镀银 添加剂 抗变色性 耐蚀性 

分 类 号：TQ153.1[化学工程—电化学工业]