FeSO_4对化学镀Ni-P工艺的影响

Effects of FeSO_4 on Electroless Ni-P Process

为了进一步改善化学镀Ni-P镀层的显微硬度和耐蚀性,将FeSO4加入到化学镀Ni-P镀液中。通过金相显微镜测试了FeSO4对Ni-P镀层表面形貌的影响;采用显微硬度计测试了镀层的显微硬度;采用电化学技术测试了FeSO4对镀层耐蚀性能的影响。结果表明:当镀液中FeSO4的质量浓度小于1.0 g/L时,镀层的沉积速率虽然降低,但仍在10μm/h以上;而且此时镀层的胞状物更加细小,镀层更加平整、致密,缺陷更少,镀层的显微硬度和耐蚀性较好;而当镀液中FeSO4的质量浓度大于1.5 g/L后,镀层的表面质量变差,镀层的显微硬度和耐蚀性均下降。

For further improving the microhardness and corrosion resistance of electroless Ni-P coating,FeSO_4 was added to Ni-P bath.The effects of addition of FeSO_4 on the morphology of Ni-P coating surface was observed with metallomicroscope;and the effects of FeSO_4 on the corrosion resistance of the coating were investigated by electrochemical technique.The results show that when the mass concentration of FeSO_4 in the bath is lower than 1.0 g/L,the deposition speed of the coating is lower,but still above 10 μm/h,furthermore,the cellular objects of the coating are further finer at this time,and the coating is still even and compact with less defects;the microhardness and corrosion resistance of the coating are better.When the mass concentration of FeSO_4 in the bath is higher than 1.5 g/L,the surface quality of the coating will become poorer,and both the microhardness and corrosion resistance of the coating will be worse.