Properties of electrodeposited Ni-S(La) coatings

Ni S(La) coatings were obtained by electrodeposition in a typical Watt bath by adding CS(NH 2) 2 and LaCl 3. The minimum HER overpotential is 75?mV. The corresponding electrochemical parameters (Tafel slope b , exchanging current density J 0) were obtained by measuring the steady state polarization curves. The content of S, La in the coating and its structure were measured by EPMA and XRD. The results show that there is no lanthanum in such coating and its structure is amorphous. From the anodic polarization curves, it is shown that the corrosion resistance of coating is very good. Based on the cathodic polarization curves during electrodeposition, it is found that LaCl 3 is benefit for amorphous coating structure to form.