Electroplating Selection Guide: Differences Between Zinc Plating, Nickel Plating, and Chromium Plating

Functions of Electroplating Layers

• Preventing material oxidation (e.g., rust prevention).

• Enhancing wear resistance.

• Improving conductivity.

• Increasing reflectivity.

• Enhancing aesthetic appearance (decorative purposes).

• Repairing dimensional inaccuracies caused by wear or machining errors.

Common Electroplating Types

1. Galvanizing (Zn)

• Process: Applying a zinc layer to the material surface.

• Hot-dip galvanizing: Immersing the material in molten zinc.

• Electro-galvanizing: Electrolytic deposition of zinc.

• Characteristics:

• Stable corrosion resistance (hot-dip galvanizing offers the best performance).

• Silver-white surface; limited resistance to strong acids/alkalis.

• Applications: Fasteners, hardware, steel structures, switch housings, etc.

• Hot-dip galvanizing produces thicker coatings for corrosion resistance.

• Electro-galvanizing provides thinner, more visually appealing coatings.

2. Nickel Plating (Ni)

• Process: Electrolytic or chemical deposition of a nickel layer.

• Applications:

• Decorative, protective, or intermediate layers (e.g., Ni → Cr).

• Dimensional restoration (thick nickel plating).

• Characteristics:

• Silver-white with a slight yellow tint.

• Moderate hardness and good wear/corrosion resistance.

• Chemical nickel coatings can be non-magnetic and uniform.

• Applications: Electronic components, molds, hardware, decorative items.

3. Chromium Plating (Cr)

• Types:

• Decorative chromium: Thin, high-reflectivity layer.

• Hard chromium: Thick, wear-resistant layer.

• Characteristics:

• High hardness (especially hard chromium).

• Excellent wear resistance and thermal stability (up to 500°C).

• Reflective surface.

• Applications: Appliance exteriors, electronic housings, mechanical shafts, molds, faucets.

Comparative Summary