NdFeB磁性材料表面化学镀Ni-Cu-P实验研究

为提高Ni-Cu-P合金镀层的耐腐蚀性,采用正交试验法对NdFeB磁体表面化学镀Ni-Cu-P合金的镀液配方和施镀工艺进行优化,获得NdFeB磁体表面化学镀Ni-Cu-P合金的最佳成分配方为:硫酸镍25g/L,硫酸铜0.4g/L,次亚磷酸钠35g/L,络合剂48g/L,缓冲剂50g/L,pH值9。分析镀液pH值和镀液中CuSO4·5H2O浓度对沉积速度和镀层成分的影响。结果表明:随镀液pH值增加,沉积速度提高,镀层中Cu和Ni含量略升高,P含量逐渐降低;随镀液中CuSO4·5H2O浓度的增加,镀层中Cu含量升高,P含量先升高后降低,Ni含量降低。

Electroless plating of Ni-Cu-P alloy on the surface of NdFeB permanent magnets

In order to improve corrosion resistance of electroless plating Ni-Cu-P coating, plating bath and plating parameters of eletroless deposition of Ni-Cu-P alloy on the surface of NdFeB magnets was optimized by an orthogonal experiment. The optimal formula of electroless Ni-Cu-P plating bath was obtained as follows: 25 g/L of nickel sulfate, 0.4 g/L of copper sulfate, 35 g/L of sodium hypophosphite, 48 g/L of complexant,50 g/L of buffering agent and pH value of 9. The effect of pH and CuSO4·5H2O content in solution on plating rate and deposit composition was investigated. It is found that the plating rate and the copper and nickel contents of the deposit increase with increasing pH, while phosphorus content decreases; with increasing CuSO4·5H2O content in solution, the copper content of the deposit increases, while the phosphorus contents first increase and then decrease with a simultaneous decrease in the nickel content.