Magnetic Coatings

Samarium Cobalt, Alnico, and Ceramic materials are corrosion resistant and do not require to be coated against corrosion. Alnico is easily plated for cosmetic qualities and Ceramics may be coated to seal the surface which will otherwise be covered by a thin film of ferrite powder.

NdFeB magnets, both sintered and bonded, are susceptible to corrosion and consideration should be given to the operating environment to determine if coating is necessary. Nickel or tin plating may be used for NdFeB magnets, however, the material must be properly prepared and the plating process properly controlled for successful plating.

Magnetic Coatings

Magnetic Coatings

Aluminum Chromate or Cadmium Chromate vacuum deposition (PVD) is a successful process that can provide a coating thickness as low as 0.0003”. Teflon, Parylene, various epoxies and other organic coatings are relatively inexpensive and are also successful as NdFeB coatings. A further option for critical applications is to apply two types of protective coatings or to encase the magnet in a stainless steel or other housing to reduce the chances of corrosion.

Magnetic Plating & Coatings

Plating neodymium magnets is an important process to protect the magnet against corrosion. The substrate NdFeB (Neodymium, Iron, Boron) will oxidize quickly without a protective layer. Below is a list of platings and their effectiveness in certian environments.

All of the Neodymium Iron Boron we stock are protected. The majority are Ni-Cu-Ni plated which consists of 3 layers (Nickel, Copper, and Nickel).

Note: All coatings / platings must be done at the factory before the magnet is saturated(charged). The magnetic field will disrupt the electroplating process, while the heat required for other types of platings would demagnetize the magnet.

Superior > Excellent > Good > Bad

Plating / Coating Indoor Use Abrasion Resistance Humidity Water Salty Air Salt Water Glue Thickness Price

Nickel (Ni-Cu-Ni)

Excellent Good Good Bad Bad Bad  Bad 10-20 Microns Low

Zinc (Zn)

Excellent Excellent Excellent Good Good Bad Good 8-10 Microns Low

Gold (Ni-Cu-Au)

Excellent Good Good Bad Bad Bad Bad 10-20 Microns High

Black Epoxy (Ni-Cu-BE)

Superior Bad Superior Superior Excellent Excellent Good 15-25 Microns Medium

Raw Epoxy (BE)

Superior Good Superior Superior Excellent Excellent Superior 10-20 Microns Medium

Plastic (ABS)

Superior Superior Superior Superior Superior Superior Excellent >800 Microns High

Teflon (PTFE)

Superior Superior Superior Superior Superior Superior Bad 250-500 Microns High

Everlube-6155

Superior Superior Superior Superior Superior Superior Good  8-25 Microns High

Xylan

Superior Superior  Superior Superior Superior Superior Good 15-30 Microns High

Parylene

Superior Superior  Superior Superior Superior Superior Good 15-30 Microns High

Advantages of Neodymium Magnet Epoxy Coating

Personalized NdFeB Magnet Cube w/ Black Epoxy Coating and Hole

Aluminium Coating Ion Vapor Deposition (IVD) Magnet for Motor Actuator Sensor

Zinc Coating Precast Shuttering Magnets NdFeB 2100kgs

57 x 5 x 5 mm Rubber Coating Long Block Neodymium Magnet Black