A permanent magnet is intended for use as a source of a constant magnetic field in electrical, automatic, radio engineering and other devices. Moreover, it allows to significantly reduce their overall dimensions and weight, while increasing autonomy and reliability. Here, the residual induction of the material for production will always be higher in relation to the magnetic flux density . One of the most effective methods of obtaining energy is a generator on a permanent magnet. This can be explained by the fact that segments entering the magnetic field commute with very low costs, in connection with the formation of poles with a polarity opposite to the main magnet. This results in the expulsion of this segment. In the event that there is another similar element, the kinematic magnetic swings begin, the principle of which is reduced to movement on the counter. This, in turn, greatly facilitates the process of entering this segment in the magnetic circuit.
Production
Constant magnets can be magnetized in both pulsed and constant fields. The intensity of the latter depends on the shape, dimensions and brand of the device. A very important nuance in this case is the level of its resistance to the impact of all sorts of external factors. First of all, this concerns temperature and demagnetizing fields. Together with this, one should not forget about shock loads and vibration. As for the shapes and sizes, they depend only on the way in which this or that permanent magnet was obtained. Among them, one can note plastic deformation, casting, vacuum deposition, and also powder metallurgy. Based on the method of production, the device has four varieties, which will be discussed in more detail below.
Varieties
A deformable permanent magnet appears as a result of the action of pressure or a cutting tool. Its high processability ensures the device competitiveness and allows using it in linear sizes up to 30 mm. Due to this, it is often used in electronic-mechanical watches. Cast options are processed by abrasive grinding and are distinguished among other types by the fact that in terms of size and shape do not have significant limitations. Proceeding from this, it is possible to meet them in the form of staples, bars, rings, cylinders and so on. The main advantage of this type of device is that the working volume is very long, which ensures high efficiency. Such a permanent magnet is most often used in magnetrons, high-power klystrons, and also in backward-wave tubes. Sputtering is carried out on a substrate, in the role of which parts of the magnetic circuit, or rather their surface, protrude. Their final magnetic characteristics of the device are obtained as a result of heat treatment. Usually they are used in retarding structures and electrical filters. Thanks to powder metallurgy, based on the system of rare earth metal , spinning permanent magnets are created. Their key characteristics are high resistance to demagnetization, low cost, compared to other types, and simple production technology. This makes them dominant in terms of output.