NdFeB permanent magnets
Neodymium magnets (NdFeB) belong to the group of rare-earth magnets. Currently, these are the most powerful magnets available, the maximum energy product of these magnets reaches up to 430 kJ/m3. The nearly linear behaviour of the hysteresis loop in the second quadrant guarantees an extremely high resistance to the action of demagnetizing magnetic fields, which are found, for example, in electric rotary machines. In their basic design, these magnets show a low corrosion resistance. For this reason, they are standardly protected by various kinds of metal and plastic coatings. By modifying the manufacturing process and by adding other chemical elements, it is possible to achieve a significant increase in the corrosion resistance, up to the weight loss level of about 1 mg/cm2 in the corrosion resistance test (HAST). The maximum currently reachable nominal temperature ranges between 220 and 230 ˚C in this type of magnets. The Curie temperature is low, approximately 310 -340 ˚C. Thermally, these magnets can be demagnetized when being heated to the temperature above 400 ˚C.
Typically, the neodymium magnets are used in electric motors and generators, magnetic couplings, magnetic separators, magnetic conveyors, magnetic clamping systems and sensors. Production for the automotive industry is controlled according to the TS 16949 standard.