(上海交通大学 金属基复合材料国家重点实验室, 上海 200030)
摘 要: 采用质量法、 X射线能谱法(EDX)及稳定常数法分别测量了镁合金直接化学镀的沉积速度、 镀层磷含量, 以及镀液稳定性随镀液使用周期的变化。 结果表明: 在镁合金化学镀工艺中, 随着使用周期的增加, 镀速和镀液的稳定常数明显下降,镀层中磷含量缓慢增加; 镀液使用超过3周期后, 由于Na+与F-离子的积累, 会产生NaF与NiF2沉淀, 沉淀的产生对化学镀过程会产生非常不利的影响。
关键字: 镁合金; 化学镀镍; 老化
magnesium alloys
(State Key Lab of Metal Matrix Composite,
Shanghai Jiaotong University, Shanghai 200030, China)
Abstract:Using mass measurement, EDX and stability constant measurement, the variations of deposition rate, phosphorous content and stability of electroless bath during the ageing of electroless nickel bath system were studied. The results show that the ageing of bath causes a dramatic declining of deposition rate and bath stability, while a slow increasing of phosphorous content of deposit. Particles of NaF and NiF2 can precipitate from the bath due to the accumulation of sodium and fluorine ions when the addition of nickel is beyond 3 metal turnovers (MTO). The precipitate has a detrimental effect on EN process.
Key words: magnesium alloys; electroless nickel plating; ageing