PERMANENT Raw Magnets
Permanent magnets are used for various applications in all areas. Depending on the requirements, the optimum Raw-magnet and the right surface coating should be selected. Motors, generators, sensors - almost everything that moves is based on magnetism.
The following magnetic materials are used in the industry
is the most powerful, commercially available permanent-magnetic material. Main alloy constituents are neodymium, and boron ferrite. His BH max. is 10 times higher than in ferrite. It is extremely hard magnetic - so immune to accidental demagnetization. The maximum operating temperature for NdFeB is 230°C. NDFEB magnets are very susceptible to corrosion and are therefore usually coated.
2. Ferrit Magnets
Main alloy constituents are ferrite, strontium and barium. Ferrite magnets reach only comparatively small magnetic forces, but have the advantage to be very inexpensive. They are not prone to corrosion and can be used at ambient temperatures up to 400°C. Ferrite magnets are the most used.
Main alloy constituents are samarium and cobalt. For the limited reserves of samarium and cobalt, SmCo magnets are very expensive. SmCo Magnets reach very high magnetic forces, only about 20% lower than the NdFeB magnets. Very advantageous is the good temperature resistance. The ambient temperatures up to 300°C allow a reliable coercivity and very low susceptibility to corrosion. A disadvantage the brittle structure and the poor machinability should be mentioned.
Major alloying constituents are aluminum, nickel and cobalt. Alnico magnets (aluminum - nickel-cobalt) are the oldest technology used permanent magnets. They achieve good magnetic holding forces about 30 % of NdFeB magnets and can be used at ambient temperatures up to 550°C. Alnico magnets are extremely hard and brittle and, due to the cobalt content are relatively expensive.
Neodymium magnets of the highest quality, we offer you in the qualities of N28-N55 to for working temperature ranges up to 230°C. Here are some examples of magnetic parameters for magnets in the working temperature range up to 80°C.
Neodymium magnets have to be surface-treated to protect against corrosion. In general, the magnets are coated. Especially for motor magnets but also recommended the process of passivation by heat treatment. The most common coatings are nickel, zinc and epoxy resin. The coatings have the following properties.
NdFeB magnet materials are produced in a press - sintering process and machined after the sintering process to produce the desired shape. Rare earth magnets are very brittle and not easy to work with. The higher is the maximum operating temperature of the material, the more brittle the material. The table below lists the physical properties of NdFeB standard material.
An important quality of NdFeB magnets is their dimensional stability, since, depending on the form of some tolerances are very difficult to comply with. You see, if possible, in the construction of unnecessary tight tolerancing from. This will facilitate the installation of the magnets. Below you will find our standard tolerances for the most common magnetic shapes.
Installation instructions for permanent magnets
Iron poles have resulted in improved power line density in the magnetic circuit. This leads to a significantly improved adhesion, as redirecting the magnetic flux and can concentrate on the adhesive surface. An approximate increase factor for the lifting capacity is given in the illustrated drawings.