Neodymium magnets coating
Neodymium magnets coating is used to protect the neodymium magnets. Sintered Neodymium is highly prone to oxidation and corrosion. Therefore the use of different coatings is essential for protection. These improve the magnet’s lifespan and ensure a high-quality product.
Plating is done after machining. It is done in different factory because of environmental laws. The plated neo magnets are then sent back to the factory for inspections.
In recent years special passivated alloys such as HAST have been developed which arrest the oxidation process without the magnet needing a more traditional, thick plating – this is coded NCNd in Magma.
Neodymium magnets coating types:
|Surface treatment||Type||Typical thickness||Color||Remarks||Recommended max. temperature|
|Silver (semi bright)||Excellent resistance to humid atmosphere|
|Ni+Cu+NI||superior resistance to humid atmosphere|
|Zinc coating||Blue Zn||8-20 µm||Silver blue||Good resistance to salt spray|
|Color Zn||Excellent resistance to salt spray|
|Tin coating||Ni+Cu+Sn||15-20 µm||Silver semi bright||superior resistance to humid atmosphere||160°C|
|Cupper coating||Ni+Cu||10-20 µm||Gold shining||Temporary treatment|
|Epoxy||Ni+Cu+epoxy||15-25 µm||black||Excellent climatic and salt spray resistance|
|Chemical coating||Ni||10-20 µm||Silver semi bright||Excellent resistance to humid atmosphere|
|Passivation||0.1-0.3 µm||Silver gray||Temporary protection||240°C|