镍包覆铁复合粉末的化学镀制备工艺研究

Preparative Process of Composite Powder for Electroless Nickel Plating onto Iron-matrix

研究了用联胺做还原剂,通过化学镀制取镍包覆的铁基复合粉末。试验选取了5个主要参数,并以此设计了L25(55)型正交试验。通过试验,优化的工艺参数为:pH值12,硫酸镍初始质量浓度25g/L,联胺初始添加量:80m l/L,镀覆温度75℃,铁粉添加量:15g/L。采用SEM、XRD对选用上述参数制取的镍包铁粉进行了分析测试。结果表明,复合粉末表面较原始粉末粗糙,颗粒明显长大,包覆层未引入杂质元素,包覆效果较好。

Composite powder for electroless nickel plating on iron-matrix is prepared by means of hydrazinc reduction. Five major parameters are selected for experimental investigation of powder preparation： initial concentration of nickelion, initial concentration of hydrazine, its pH value, plating temperature,addition amount of iron powder, and an orthogonal test L25 （ 55 ） is designed accordingly. A great number of experiment are performed to get optimal technological parameters as follows ： initial concentration of nickel sulphate is 25 g/ L, initial concentration of ydrazine is 80 ml/L, pH value is 12, plating temperature is 75 ℃, addition amount of iron powder is 15 g/L. SEM and XRD are used to analyze the power tor nickel plating onto iron. The results show that the surface of plating with such powder is rougher than that with original powder and the particles of the powder grew greatly. There is also no inclusion inside the coating layer. It suggests that the plating effect is preferable.