How to overcome the problem of NdFeB magnets being prone to corrosion in humid environments to improve their service life?

Neodymium iron boron (NdFeB) magnets have been widely used in many fields such as electronics, automobiles, medical equipment, wind power generation, etc. due to their excellent magnetic properties. However, this powerful magnet is prone to corrosion in humid environments, which affects its magnetic properties and service life, becoming one of the bottlenecks restricting its widespread application.
1. Understanding the corrosion mechanism
First of all, it is crucial to understand the corrosion mechanism of NdFeB magnets in humid environments. NdFeB magnets are mainly composed of neodymium, iron, boron and other elements. These elements are prone to chemical reactions with oxygen, moisture and possible chloride ions in the air under humid conditions, resulting in surface oxidation and rust, which in turn affects the magnetic properties and structural integrity of the magnet.
2. Surface treatment technology
Electroplating: By plating a layer of corrosion-resistant metal (such as nickel, zinc, chromium, etc.) on the surface of the magnet, a protective barrier is formed to effectively isolate the magnet from direct contact with the environment and reduce the possibility of corrosion. The electroplating layer not only improves the corrosion resistance of the magnet, but also improves its appearance and wear resistance.
Chemical conversion film: such as phosphate conversion film (phosphating), a dense protective film is formed on the surface of the magnet through chemical reaction. This film can effectively block the intrusion of moisture and corrosive media and improve the corrosion resistance of the magnet.
Organic coating: Magnets are coated with organic materials such as epoxy resin and polyurethane. These coatings not only have good anti-corrosion properties, but also provide certain insulation and mechanical strength to protect the magnets from physical damage and chemical erosion.
3. Environmental control
Reduce humidity: By installing dehumidification equipment and using desiccants, the humidity of the magnet storage and use environment is kept low to reduce the erosion of moisture on the magnet.
Sealed packaging: Place the magnet in a sealed container and fill it with desiccant or inert gas (such as nitrogen) to isolate the external humid air and extend the shelf life of the magnet.
Regular inspection and maintenance: For magnets that are in a humid environment for a long time, regular appearance inspection and performance testing should be carried out to promptly detect and deal with possible corrosion problems to avoid further deterioration of corrosion.
4. Material Improvement
Alloying: By adjusting the alloy composition of NdFeB magnets, adding some elements that can improve corrosion resistance (such as dysprosium, cobalt, etc.), starting from the material itself, the corrosion resistance of the magnet is improved.
Amorphous alloy: Research and develop amorphous NdFeB magnets. This type of material usually has higher corrosion resistance and better magnetic properties, which is one of the future development directions.