Neodymium magnets (NdFeB) belong to the group of rare-earth magnets. At present, these are the strongest magnetic materials available. An almost linear behaviour of the hysteresis curve in the second quadrant provides an extremely high resistance to effect of demagnetizing magnetic fields that occur for example in electric rotating machines. In the basic version, these magnets show a low corrosion resistance. Therefore, as standard they are protected by means of various types of metal and plastic coatings. Modification of the manufacturing process and addition of other chemical elements can result in a considerable increase of the corrosion resistance up to the level of a mass decrement about 1 mg/cm2 during the corrosion resistance test HAST. The maximum rated temperature of this type of magnets achievable at present is in the range from 220 and 230°C, the temperature stability verified by a decrease in the magnetic moment at the rated temperature achieves the level of 3% at L/D=0.46. The Curie temperature ranges from 310 to 340˚C, these magnets can be thermally demagnetized by heating them at temperature above 400˚C.
Use of neodymium magnets
The neodymium magnets are usually used in electric motors and generators, magnetic couplings, magnetic separators, magnetic conveyors, magnetic holders and sensors. Manufacturing for the automotive industry is controlled according to the standard IATF 16949.
The NdFeB-based magnetic materials, we deliver for the demanding electrotechnical applications, such as electric motors and generators, show the following extraordinary properties:
- corrosion resistance (test HAST, up to 1mg/cm2)
- temperature stability (up to 3%)
- remanent induction spread within one production batch - 1.5%