碱金属阳离子对化学镀镍的影响

摘要

The effects of alkali metal cations (dosed as citrates with a concentration of 0.143 mol/L) on phosphorus content, deposition rate, corrosion resistance to nitric acid and appearance of electroless Ni coating on brass substrate were studied with a bath containing NiSO4·6H2O 25 g/L, NaH2PO2·H2O 25 g/L, glycine 1 g/L, ammonium acetate 4.5 g/L, and lactic acid 1 mL/L. The results showed that the phosphorus content and corrosion resistance to nitric acid are in the following order: Na+ ＜ K+ ＜ NH+. The deposition rate is in the order ofNa+ ＞ K+ ＞NH+. The plating solution was found to easily remain on the coating produced by the formulation 2 (containing K+), leading to oxidation discoloration of the coating.%研究了碱金属阳离子(以柠檬酸盐的形式加入,浓度为0.143 mol/L)对黄铜基体上化学镀层中镍磷含量、化学沉积速率、镀层耐硝酸腐蚀性能和镀层外观等的影响.镀液基础配方为:NiSO<,4>·6H<,2>O 25 g/L,NaH<,2>PO<,2>·H<,2>O 25 g/L,甘氨酸1g/L,乙酸铵4.5 g/L,乳酸1 mLFL.结果表明:镀层中磷含量和耐硝酸腐蚀性能按Na<'+>的顺序排列,化学沉积速率按Na<'+K<'+NH<'+><,4>的顺序排列,配方2(K<'+>)镀层易残留镀液,导致镀层氧化变色.