Neodymium magnets have poor resistance to corrosion. In order to protect the neodymium magnet from corrosion, usually, neodymium magnet will be plated.
The most common coating for Neodymium magnets
is Nickel + Copper + Nickel (Ni + Cu + Ni). This coating offers the
magnet relatively good protection from corrosion and passive
applications. If the magnet will be exposed to moisture or liquid then
consider the use of an organic coating such as Epoxy. A hard wearing
coating, Epoxy is suited to applications where the magnet will come
under some friction or knocking. Meanwhile, other options for coating
are Color Zinc, Zinc, Epoxy resin, Silver, Gold, Tin, and so on.
Surface Coating of Neodymium Magnet
| Type | Picture | Plating | Thickness(microns) | Color | Resistance |
| Nickel |  | Ni | 10-25 | Bright Silver | Excellent against Humidity |
| Ni+Cu+Ni | |||||
| Ni+Epoxy resin | Black, Grey | ||||
| Zinc |  | Zn | 8-15 | Bright Blue | Good Against Salt Spray |
| C+Zn | Light Blue Tint | ||||
| Znic Cr3+ |  | Zn | 8-15 | Bright Blue | Good Against Salt Spray |
| C+Zn | Light Blue Tint | Excellent Against Salt Spray | |||
| Epoxy |  | Epoxy | 15-25 | Black, Grey | Excellent Against Humidity & Salt Spray |
| Ni+Cu+Epoxy | |||||
| Zn+Epoxy | |||||
| Tin |  | Ni+Cu+Sn | 15-20 | Silver | Superior Against Humidity |
| Au |  | Ni+Cu+Au | 10-20 | Gold | Superior Against Humidity |
| Ag |  | Ni+Ag | 10-20 | Silver | Superior Against Humidity |
| Everlube |  | Ni+Cu+Everlube | 10-20 | Pale Gold | Superior corrosion & Salt Spray |
| IVD AI |  | AI | 5-25 | Silver White | Excellent adhesive force, high temperature resistance |
| Parylene |  | Parylene | 5 -20 | Transparent | Superior corrosion & Salt Spray |
| Passivation |  | No coating | 1- 3 | Silver Grey | Temporary Protection |
