Rubber magnets have good corrosion resistance, which is mainly attributed to the following aspects:
Rubber magnets are made by compounding bonded ferrite magnetic powder with synthetic rubber. The outer rubber material serves as a protective film, which can prevent external corrosive substances from directly contacting the internal magnetic materials. For example, in some humid environments, it is difficult for moisture to penetrate the rubber layer to corrode the internal magnetic powder. This rubber-coated structure is like putting a "protective coat" on the magnet, largely isolating the magnet from the erosion of air, moisture, and some chemical substances.
As the main magnetic component of rubber magnets, ferrite magnetic powder has relatively good chemical stability. Ferrite itself is a metal oxide and has a certain resistance to many chemical substances at room temperature. Compared with some metal magnetic materials that are easily oxidized (such as neodymium-iron-boron magnets), after the ferrite magnetic powder is made into rubber magnets and combined with the protection of rubber, it can maintain good stability in environments containing certain amounts of salt, acid, and alkali components.
In practical applications, rubber magnets can work normally in a variety of potentially corrosive environments. For example, in outdoor advertising displays, rubber magnets may experience long periods of exposure to sunlight and rain. They are exposed to environments containing complex components such as rainwater (which may contain acidic substances) and dust, but they can still maintain the integrity of their magnetism and structure. In household appliances such as refrigerators and disinfection cabinets, rubber magnets also come into contact with some cleaner residues, water vapor, etc., but they can still play a stable role for a long time, which fully demonstrates their good corrosion resistance.
However, the corrosion resistance of rubber magnets is not absolute. If they are exposed to strongly corrosive chemical substances (such as high-concentration strong acids and alkalis) for a long time or in extreme environments with high temperature, high humidity, and a large amount of corrosive gases, the rubber layer may be gradually damaged, which will then affect the stability of the internal magnetic materials and lead to a decline in the performance of the rubber magnets.
