SF-522型氯化钾镀锌添加剂及其镀层性能

Properties of SF-522 additive for potassium chloride zinc plating and zinc coatings obtained

对比研究了SF-522型添加剂和国外某进口添加剂对氯化钾镀锌液及所得镀层性能的影响。镀液组成与工艺为:KCl200g/L,ZnCl250g/L,H3BO335g/L,柔软剂30mL/L,光亮剂1.5mL/L,温度25°C,时间25min,电流密度2A/dm2。无锌基础液的阴极极化曲线表明,SF-522型添加剂和国外某进口添加剂在抑制析氢和增强极化方面的性能相近;光亮范围、分散能力、覆盖能力等镀液性能测试结果同样表明二者的性能相近。从含SF-522型添加剂镀液中所得镀层的耐蚀性略优于从含进口添加剂镀液中所得镀层;二者的结合力均合格;前者表面平滑,只存在少量微孔,其微观形貌明显优于后者。

The effects of SF-522 additive and an imported additive on potassium chloride zinc plating bath and the properties of the obtained coatings were compared. The composition of plating bath and operation parameters are as follows： KC1 200 g/L, ZnC12 50 g/L, H3BO3 35 g/L, softener 30 mL/L, brightener 1.5 mL/L, temperature 25 ℃, current density 2 A/dm2, and time 25 min. The cathodic polarization curves of zinc-free basic bath showed that the effects of SF-522 and the imported additives on inhibition of hydrogen evolution and strengthening of polarization are similar. The baths containing the two additives have similar performance in the tests of bright range, throwing power, and covering power. The coating prepared from the bath containing SF-522 additive has slightly better corrosion resistance than that prepared from the bath containing the imported additive. The adhesion of both coatings is qualified. The former is smooth and has small amount of micro-pores, showing better microscopic morphology than the latter.