Surface Treatment

The surface of rare-earth permanent magnets is usually corroded by humidity, acid, alkaline solutions and harmful gases. So surface treatment has to be done to protect the magnets.

Surface Method Thickness (µm) Colour
Ni Electroplate ≥10 Silver semi-bright
Zn Electroplate ≥10 Silver semi-bright
Ni+Sn Electroplate Ni≥5
Sn≥10
Silver semi-bright
Aluminum Chromate Ion-deposition ≥5 Yellow semi-bright
Resin Coatings Spray Painting
Electrophoresis
≥20 black
surface treatment
surface treatment