高磷化学镀镍磷合金工艺优化

Optimization of electroless plating process for high-phosphorus nickel–phosphorus alloy

采用正交试验对化学镀镍–磷合金镀液的添加剂进行优化。基础镀液组成和工艺条件为:NiSO4·6H2O26 g/L,NaH2PO2·H2O 30 g/L,CH3COONa·3H2O 16 g/L,柠檬酸21.5 g/L,88%乳酸5 m L/L,OP-10 5 mg/L,p H 4.80±0.2,温度(88±2)°C,时间2 h。探讨了添加剂苯骈三氮唑(BAT)、苯并咪唑(BMI)、氨三乙酸(NTA)和硫酸高铈对镀速、镀层光泽度和磷含量的影响。4种添加剂的最优组成为:BAT 1.0 mg/L,BMI 10 mg/L,NTA 0.5 g/L,Ce(SO4)2·4H2O 6 mg/L。采用该组合添加剂进行化学镀Ni–P合金时,镀速为10.92μm/h,镀层光泽度和磷含量分别为225 Gs和12.96%,表面均匀、致密、平整。

The additive compositions of nickel-phosphorus alloy plating bath were optimized by orthogonal test. The basic bath composition and process conditions are as follows： NiSO4·6H2O 26 g/L, NaH2PO2·H2O 30 g/L, citric acid 21.5 g/L, CH3COONa·3H2O 16 g/L, 88% lactic acid 5 mL/L, OP-10 5 mg/L, pH 4.80 ± 0.2, temperature （88 ± 2） ℃, and time 2 h. The effects of different additives including benzotriazole （BAT）, benzimidazole （BMI）, nitrilotriacetic acid （NTA）, and cerium（IV） sulfate on deposition rate, glossiness, and phosphorus content of NiP coating were discussed. The optimal compositions of the four additives are as follows： BAT 1.0 mg/L, BMI 10 mg/L, NTA 0.5 g/L, and cerium（IV） sulfate 6 mg/L. Using the given composition of additives, an uniform, compact, and level Ni-P alloy coating can be obtained with a deposition rate of 10.92 μm/h, glossiness of 225 Gs, and phosphorus content of 12.96%.