氯化钾无氰镀镉故障的处理措施

Countermeasures for troubles occurred in cyanide-free potassium chloride cadmium plating

描述了新型氯化钾无氰镀镉出现的几例故障和应对措施。配位剂含量过高时,镀液容易浑浊;氯化镉含量过低时,低电流密度区沉积速率太慢;镀液pH偏低时低电流密度区镀层粗糙,偏高则高电流密度区镀层粗糙;添加剂的分解产物过多会导致镀层粗糙,需定期用活性炭处理镀液。根据生产经验,将部分工艺参数调整为:氯化镉25~35g/L,配位剂90~140g/L,氯化钾140~180g/L,镀液pH=6.5~7.5。氯化镉与配位剂的浓度范围扩大明显提高了工艺的可操作性。

Some troubles occurred in novel cyanide-free potassium chloride cadmium plating bath and their countermeasures were described. The plating bath becomes turbid when the concentration of complexing agent is too high. The deposition rate is decreased greatly in low current density area when the concentration of cadmium chloride is too low. Rough coating will be formed in low current density area at low pHs, and in high density area at high pHs. The excessive accumulation of the decomposition products of additives makes the cadmium coating being rough, and the plating bath needs to be regularly treated with activated carbon. Some process parameters were adjusted based on the production experience： cadmium chloride 25-35 g/L, complexing agent 90-140 g/L, potassium chloride 140-180 g/L, and pH 6.5-7.5. The extension of the concentration ranges of cadmium chloride and complexing agent greatly improves the operability of the process.