zinc cobalt rack and barrel plating and black passivate

Zinc Cobalt Plating

Zinc cobalt is a sacrificial coating that will continue to prevent corrosion to the substrate even if a scratch penetrates down through the coating.
The zinc deposits can be further enhanced by alloying with small amounts of Cobalt. This deposit is plated from an alkaline bath with the level of Cobalt in deposit at 0.4-1.0%.
The plating of articles from this solution can be carried out by either a rack or barrel operation.
Zinc Cobalt deposits can be passivated in a Black passivate or in a bronze type passivate