以硫酸镍为主盐的镁合金化学镀镍

Electroless nickel plating on magnesium alloy in solution with NiSO_4 as main salt

以硫酸镍为主盐,采用正交实验确定了镁合金'无氟绿色环保'碱性化学镀镍镀液成分及操作条件.选择适合镁合金化学镀的缓冲剂,考察了镀液参数对化学镀的影响.结果表明:缓冲剂Na2CO3适合镁合金化学镀镍,它不仅能提高化学镀镍速度,而且可以调节镀层与基体间的结合力,缓冲化学镀过程中pH值的变化;碱性化学镀的pH值范围为8.5～11.5;络合剂柠檬酸钠的最佳浓度为30 g/L;所得镀层均匀致密,孔隙率少,属于晶态特征明显的低磷镀层,耐蚀性较好,化学镀层与镁合金基体结合良好.

The electroless nickel-plating on magnesium alloy was studied, using NiSO_4 as the main salt in the electroless plating alkaline solutions. The effects of the buffer agent and plating parameters on the properties and structures of the plating coatings on magnesium alloy were investigated in detail. The compositions of the non-fluoride and environmentally friendly plating bath were optimized through Latin orthogonal experiment. The buffer agent (Na_2CO_3) added to the plating bath was found to be useful in increasing the growth rate of the plating coating, adjusting the adhesion between the electroless plating coatings and the substrates, and maintaining the pH value within the range of 8.5-11.5, which is required for the successful electroless nickel-plating on magnesium alloy with (NiSO_4) as the main salt. Trisodium citrate dihydrate was found to be an essential component of the plating bath to plate magnesium alloy, with an optimum concentration of 30g/L. The obtained plating coatings are crystalline, having advantages such as low-phosphorus content, high density, low-porosity, good corrosion resistance and strengthened adhesion.