Neodymium magnet contains oxides such as Nd and Fe which is easy to get rusty. And oxidation will damage magnet body and reduce magnetic force day by day. Therefore coating is an essential part of neodymium magnet. Many layers can be used covered NiCuNi, Zn, silver, gold epoxy, phosphorization and passivation etc. Different coatings lead to different antioxidant effect. Even with the same coating, types and quality of electroplating process also affect the results. For neodymium magnet which operates in the rain and other harsh environments, the requirement for coating is stricter. Salt spray test is the common method applied to inspect magnet coating.

What Is Salt Spray Test (SST)

The salt spray test, a standardized and popular corrosion test method, is applied to inspect corrosion resistance of materials and surface coatings. Usually, the test materials are metallic and finished with a surface coating which can provide a degree of corrosion protection to the underlying metal. With the help of salt spray tester, it is accelerated corrosion test that produces a corrosive attack to coated samples in order to predict the suitability of the coating in use. The test result is evaluated by the appearance of corrosion products (oxides) after a period of time.

Salt spray test chamber:

Test condition:

Test duration from 24 hrs, 48 hrs, and 72 hrs to 500 hrs depends on the corrosion resistance of the coating
Normal Test Condition: 5%NaCl (aq), 100%RH, 35℃

If your neodymium magnet have special requirement for salt spray test hours, please point out when enquiry; China Magnets Source Material Ltd will produce magnet according to your specification.

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