Corrosion resistance of ultrasonic electrodeposited Ni-Co-Fe ternary alloy films according to current density.

Ni-Co-Fe ternary alloy films were deposited on Copper clad laminate (CCL) by ultrasonic electroplating at different current densities from a sulfate bath. The corrosion properties of the ultrasonically-electrodeposited Ni-Co-Fe films were investigated by electrochemical impedance spectroscopy (EIS). We found that Ni, Co, and Fe component ratios changed according to the current density. The Ni content increased when the current density increased, but the Co and Fe content of the films decreased. Ni-Co-Fe ternary alloy films with a high Ni content and lower Fe content showed good resistance to corrosion. We also found that ultrasonically-electrodeposited Ni-Co-Fe films had higher corrosion resistance than non-ultrasonically electrodeposited Ni-Co-Fe films. Ultrasonically electrodeposited Ni-Co-Fe films had a higher Ni content than electrodeposited Ni-Co-Fe ternary alloys. X-ray diffraction analysis revealed that the Ni-Co-Fe films comprised a mixture of both FCC (face centered cubic) and BCC (body centered cubic) structures.