环保无氰镀镉工艺可行性研究

Feasibility study on environment-friendly cadmium plating technology without cyanide

无氰镀镉溶液的分散能力和深镀能力优异,当电流密度为1.16~1.37 A/dm^(2),镀液温度在22~35℃时,镉层的沉积速率约为10.00~16.23μm/h。镉层外观初期为带金属光泽的瓦灰色,当镀液通电量逐渐增加时,镉层外观逐渐变成银灰色、银白色,钝化后为彩虹色。镉层结合力、耐蚀性、氢脆性均符合HB5036—1992的要求。通过霍尔槽试验、经验数据、镉层外观等作为依据补加主盐、导电盐、添加剂,可以保证镉层的外观和沉积速率。在镉层上制备氧化磷化膜,膜层外观和耐蚀性符合工艺要求。小零件的试镀效果良好,满足交付标准。

The experiment showed that the dispersing ability and deep plating ability of the cyanide-free cadmium plating solution were excellent.When the current density was 1.16-1.37 A/dm^(2)and the bath temperature was 22-35℃,the deposition rate of cadmium layer was 10.00℃-16.23μm/h.The initial appearance of the cadmium layer was tile gray with metallic luster,and when the amount of electricity in the plating solution gradually increased,the appearance of the cadmium layer gradually became silver gray and silver white,and the appearance of the cadmium layer after passivation was rainbow color.The binding force,corrosion resistance and hydrogen brittleness of the cadmium layer met the requirements of HB5036-1992.The appearance and deposition rate of cadmium layer can be guaranteed by adding main salt,conductive salt and additives according to hall chamber test,empirical data and appearance of the cadmium layer.The oxidation phosphating film was prepared on cadmium layer,and the appearance and corrosion resistance of the film met the technological requirements.The test plating effect of small parts was good and met the delivery standard.