溶液老化对化学镀镍层耐蚀性的影响

THE EFFECT OF SOLUTION AGE UPON THE CORROSION RESISTANCE OF ELECTROLESS NICKEL DEPOSITS

化学镀镍液的老化能对其镀层性能产生重大影响。随着镀液的使用,硫酸盐、亚磷酸盐及其他盐都积累起来而开始影响镍、磷的沉积,从而使镀层的内应力、孔隙率增大而耐化学性下降。本文叙述了为使化学镀镍液老化对镀层性能的影响定量化而进行的一系列试验与结果,叙述了为确定亚磷酸盐、硫酸盐的影响而作的试验并对所观察到的变化提出可能原因。

The age of an electroless nickel plating solution can have a significant effect upon the bath and upon the properties of its deposit. As the bath is used, sulfates, phosphites, and other salts accumulate, and begin to affect the deposition of nickel and phosphorus. This, in turn, causes the deposit's internal stress and porosity to increase and its chemical resistance to decline. This paper describes the results of a series of tests conducted to quantify how the age of the plating solution affects the properties of its electroless nickel deposit. It also describes tests conducted to establish the effect of orthophosphite and sulfate accumulation and suggests possible causes for the changes that were observed.