How to Solve the Moisture-proof and Anti-oxidation Problems of Bonded NdFeB Magnets?
Friends who have a little understanding of magnets know that compared with ferrite magnets, NdFeB magnets have high remanence, high coercivity, high magnetic energy product, high performance and price ratio, and are easy to process in various sizes. And the minimum specification, making its own volume weight and the volume weight of the motor made of it reduced by 5 to 10 times. Therefore, more expensive prices are gradually accepted by people. Therefore, its usage is getting bigger and bigger, and its uses are getting wider and wider.
However, the anti-corrosion performance of bonded NdFeB magnets is poor. Nd and Fe in the magnets have strong chemical activity and are easily oxidized. Micro-batteries are formed on the surface of the magnets in a humid environment, which increases the corrosion rate. Corrosion will cause different degrees of deformation of the magnets. So the problem of corrosion resistance of NdFeB magnet is one of the key problems affecting its application. At present, surface electrophoresis is usually used to improve its corrosion resistance.
The moisture-proof and anti-oxidation of bonded NdFeB magnets generally have the following methods:
The surface treatment of bonded NdFeB magnet products is mainly treated by epoxy resin [electrophoresis], in addition to acrylic resin electrophoresis, which can make the product excellent in corrosion resistance and have higher corrosion resistance.
2. Spraying method:
Epoxy resin spraying, Teflon spraying,
3. Other special requirements:
Parylene deposition, vacuum dipping
The production and application development of bonded NdFeB permanent magnet materials is relatively late, the application is not wide, and the amount is small, mainly used in office automation equipment, electrical machinery, audio-visual equipment, instrumentation, small motors and measuring machinery, in mobile , CD-ROM, DVD-ROM drive motor, hard disk spindle motor HDD, other micro DC motors and automation instruments and other fields are widely used. In recent years, the application proportion of bonded NdFeB permanent magnet materials in my country is as follows: computers account for 62%, electronics industry accounts for 7%, office automation equipment accounts for 8%, automobiles account for 7%, appliances account for 7%, and others account for 9%.
The above problems have also been studied, and the research results have been applied to production practice. The produced bonded NdFeB multi-pole magnetic rings have been used by more than 20 users to assemble and produce more than 3 million permanent magnet stepping motors, and the motors have been assembled into printers, household telex machines, fax machines, etc. Air conditioners, copiers, robots and car odometers have all been well received by users.