酸性氯化铵镀锌层变色问题研究

Study on discoloration of zinc coating prepared from acid ammonium chloride zinc plating bath

从镀液硫脲含量以及钝化后的烘烤和封闭工艺这三方面探讨了酸性氯化铵体系镀锌层的变色问题。结果表明,镀锌液中硫脲含量过高和钝化膜干燥不彻底均会导致镀层变色。对钝化膜进行封闭处理可有效防止镀锌试样变色。

The discoloration problem of zinc coating prepared from acid ammonium chloride bath was discussed from three aspects including thiourea content in plating bath, baking process conditions, and sealing after passivation. The results showed that both excessive thiourea in zinc plating bath and incomplete drying of passivation film can cause the discoloration of zinc coatings. The discoloration of electroplated zinc coatings can be effectively prevented by sealing on passivation film.