镀层Cu含量对Ni-P-Cu镀层性能及电化学行为的影响

The effect of Cu content on the properties and electrochemical behavior of electroless Ni-Cu-P coatings

通过调整镀液中Cu离子浓度和添加剂成分,得到了具有不同Cu含量的Ni-Cu-P三元镀层。使用SEM、XRD、DSC、电化学测试等设备和手段研究了镀层性能,总结了Cu含量对Ni-Cu-P镀层性能的影响。结果表明,Cu含量越高的镀层具有越小的沉积颗粒和越致密的镀层结构。Cu元素的加入会降低镀层中P的含量,增加镀层的有序度。极化曲线测试表明,由于镀层结构和化学组成的改变,Cu含量较高的镀层具有更低的孔隙率,更高的耐蚀性。交流阻抗测试证实了该结果,并表明随Cu含量增大,三元镀层的腐蚀行为随之变化。

Ni-Cu-P coatings with different Cu content were prepared by changing the concentrations of Cu ions and additives in the plating baths. SEM, XRD, DSC and electrochemical tests were employed to investigate the relationship between Cu content and the properties of the coatings. It＇s indicated that the increase of Cu content promotes the deposited particles fine and the coating structure dense. The introduction of Cu to the coating de- creases the P content and increases the ordered degree of the coating. Polarization curves of the coatings showed that the coatings with higher Cu content exhibited higher corrosion resistance with lower porosity, higher corro- sion potential and lower corrosion current density. The results of EIS tests confirmed this result and revealed that the corrosion behavior changed along with the increase of the Cu content of the coating.