How to detect the coating quality of NdFeB powerful magnet?

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Due to the poor corrosion resistance of NdFeB magnet, it is necessary to improve the corrosion resistance by electroplating. Most magnet manufacturers are outsourcing to professional electroplating manufacturers for coating treatment. What is the process flow of strong magnet electroplating? How to detect the coating quality of strong magnet? What are the general coatings of magnets?
Strong magnet electroplating process flow (suitable for automatic production line): hole sealing → solidification → vibrating light → feeding → ultrasonic oil removal → water washing → water washing → acid washing → water washing → water washing → water washing → water washing → water washing → activation → water washing → water washing → pre nickel plating → bright nickel → recycling → water washing → water washing → water washing → sealing → water washing → hot drying → blanking → drying

How to detect the coating quality?

The quality of the coating has a direct impact on the service life of Nd-Fe-B:
1. Visual inspection of appearance
The appearance is mainly observed by naked eyes, and it is best under natural light (sunlight, non direct light), or under fluorescent lamp with illumination equivalent to 40W. There should be no blistering, peeling, local plating and uneven tone, stains, water stains, etc.
2. Coating thickness measurement
3. Drop test (mainly for galvanized products)
4. Grid test (generally used for nickel plated products)
5. Chilling and heating test
6. PCT pressure test
7. SST salt spray test
8. Constant temperature and humidity test, etc

What does NdFeB permanent magnetic material coating have in general?

Zinc plating, black zinc plating, nickel plating, black nickel plating, silver plating, gold plating, epoxy plating, baking paint, etc.

How long does it take to electroplate a strong magnet?

It depends on the nature of the customer’s product, and whether it needs to pass the salt spray test. If it needs to pass the salt spray test, the electroplating time will be prolonged, and it is 3-4 hours that is not required!

What are the reasons for peeling and rust of NdFeB magnet coating?

For qualified electroplating products, under normal conditions, the electroplating coating should not appear rust. When it is too humid, the air circulation is not good, and the temperature difference changes greatly, even the qualified products in the salt spray test may produce rust spots when they are stored in the harsh environment for a long time. When the electroplating products are stored in a harsh environment, the base layer will react with the condensate water further, which will reduce the adhesion between the base layer and the coating. In serious cases, it will also cause local powdering of the base layer, and then natural peeling. Electroplating products should not be placed in a place with high humidity for a long time, but in a cool and dry place.

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