Zn-Ni alloy coatings (usually composed of approximately 85% zinc and 15% nickel) are electroplated on carbon steel as a protective coating in a process similar to the way zinc coatings are applied. Zn-Ni coatings typically consist of 8 to 14 µ m layer of 12 to 16% nickel alloy next to the substrate topped by a 0.06 to 0.15 µ m trivalent passivate layer and a 0.5 to 4.0 µ m top coat layer.
Zn-Ni alloy coating significantly exceeds the protection offered by other coatings in three main areas:
• It offers greater corrosion protection.
• It provides more wear resistance in moving parts.
• It limits thermal stress to parts subjected to higher operating temperatures.