Abstract
Ni-Fe alloy shots (Ni-50% Fe) in a titanium basket were used as the anode for the electrodeposition of bright Ni-Fe alloy coatings from a dilute Watts type bath.
Active dissolution of the Ni-Fe alloy anode in the plating bath was observed; however, the surface roughness of the anode increased slightly with increases in plating time. The anode efficiency was found to be close to 100% during prolonged electrolysis. Continuous electrolysis using the initial nickel plating bath and Ni-Fe alloy anode for 24 hours at 5A/dm2 resulted in an increase in Fe2+ and a decrease in Ni2+ in the bath leading to a gradual increase in Fe content in the Ni-Fe alloy deposits.
The hardness of the Ni-Fe alloy deposits obtained at pH 3.2 and 50°C was found to be 520-560Hv when Fe content was 12-38wt%. Microscopic observation of the alloy deposits revealed that the bright Ni-Fe alloy coatings had a banded microstructure. Effects of the Fe content on the X-ray diffraction profiles of the Ni-Fe alloy deposits obtained was also examined.
These results suggest that the metallurgically produced Ni -Fe alloy shots are acceptable anode material for the electroplating of Ni-Fe alloy coatings.
