辅助配位剂对丁二酰亚胺无氰镀银层性能的影响

Effect of auxiliary complexant on properties of silver coatings electroplated from cyanide-free succinimide bath

以含羧基化合物A或其铵盐B,又或焦磷酸钾作为辅助配位剂进行无氰电镀银。镀液的基础组成和工艺条件为:硝酸银5 g/L,丁二酰亚胺60 g/L,硼砂5~10 g/L,pH=9.5±0.5,温度20~30℃,磁力搅拌,时间30 min。研究了3种辅助配位剂对无氰电镀银光亮电流密度范围及银层光泽、结合力和表面形貌的影响。结果表明,采用化合物含羧基铵盐化合物B作为辅助配位剂时光亮电流密度范围为0.020~0.867 A/dm^2,所得银层的光泽高达579 Gs,结合力良好,组织结构受电流密度的影响较小。

Silver electroplating was conducted in a cyanide-free bath comprising silver nitrate 5 g/L,succinimide 60 g/L,borax 5-10 g/L,and auxiliary complexant(carboxyl-containing compound A or its ammonium salt B,or potassium pyrophosphate)at temperature 20-30℃and pH 9.5±0.5 under magnetic agitation for 30 min.The effects of different auxiliary complexants on the current density range for electroplating a bright silver coating,as well as its gloss,adhesion,and surface morphology were studied.The results showed that the current density range for electroplating a bright silver coating was 0.020-0.867 A/dm^2 when using the carboxyl-containing ammonium salt compound B as auxiliary complexant.The silver coating featured a gloss up to 579 Gs and good adhesion,and its structure was slightly affected by the change of current density in the said range.