Coatings for Neodymium Magnets
Special requirements of an application or the magnet material itself – NdFeB in non-corrosive design – can make it necessary to provide magnets with a coating. However, there is no universal coating, the respective coating must be adapted to the application.
Metallic and Organic coating for neodymium magnets
- Metallic coatings offer good protection against moisture and vapor, especially as multiple layers. But they can still be damaged in corrosive media. Metallic coatings such as Nickel coating are suitable for all sintered neodymium magnets.
- Organic coatings are more resistant to aggressive media, but are usually less suitable for mechanical loads on the magnets. Organic coatings can be used on all types of permanent magnets.
Coating type | Thick (μm) | Color | WorkingTemp. (°C) | PCT (h) | SST (h) | Characteristics |
White Zn | 5-20 | Blue and White | ≤160 | – | ≥48 | Anodic coating, low cost |
Colored Zn | 5-20 | Iridescent | ≤160 | – | ≥72 | Anodic coating, low cost |
NiCuNi | 10-30 | Silver White | ≤390 | ≥96 | ≥48 | High temperature resistance |
PVD Al | 5-25 | Silver White | ≤390 | ≥96 | ≥96 | Excellent adhesive force, |
Epoxy | 15-25 | Black | ≤200 | – | ≥360 | Insulation, excellent thickness consistency |
NiCu+Epoxy | 20-40 | Black | ≤200 | ≥480 | ≥720 | Insulation, excellent salt spray resistance |
NiCuNi+Au | 10-30 | Golden | ≤200 | ≥480 | ≥72 | good for decoration, excellent durability, |
Spray Epoxy | 10-30 | Black | ≤200 | ≥192 | ≥504 | Insulation, high temperature resistance |
Phosphating | – | – | ≤250 | – | ≥0.5 | low cost, temperory protection |
