Research of mechanical properties of permanent magnets for magnetic circuits of electrical machines

The permanent magnets are used in the constructions of the various electric devices such as motors or generators. They are also used in clutches, ABS systems, speakers, microphones, sensors and magnetic handles. Mechanical resistance of hard magnets is a very important factor, which may have an impact on the decision whether the given application may be possibly used. An optimal mechanical resistance of the hard magnets depends on the motor construction. First of all, it is important whether the hard magnet is located in rotor or stator. The other factors impacting the selection of the hard magnet are: the mounting method of the magnets and the fact whether the magnets were magnetized before or after the motor was assembled. These factors affect the type and size of mechanical stresses occurring in the magnet during the operation of the given device. In this article were presented the results of the measurements of the magnetic properties of: sintered ferrite permanent magnets, sintered magnets made from an alloy of Nd- Fe-B and SmCo and bonded magnets bonded with a substance, so-called dielectromagnets. New magnetic materials and the less expensive production technology enables the designers of the devices to construct the modern and low-energy electric motors. In the measurements were used the hard magnetic powders produced by Magnequench and Yuxiang