What are permanent magnets? what are their applications?
Permanent magnets are magnetic products that can have different forces depending on their different material, shape and size.
What is a permanent magnet?
Permanent magnets are materials with different magnetic forces. You can use ferromagnetic materials such as iron, which attracts and repels the same poles as, for example, the south and south poles or the north and north poles with each other. Magnetic forces are always maintained unless the material is exposed to high temperatures, strong mechanical stresses or powerful magnetic fields.
Mutual poles attract each other, which means that the north pole of one magnet is the south pole of another magnet. On the other hand, in the case of the same poles, a repulsive force acts, which means that the north pole of one magnet repels the north pole of another magnet. Permanent magnets usually attract ferromagnetic substances such as cobalt, iron, nickel and some alloys.
Unlike permanent magnets, electromagnets require power to create a magnetic field. Permanent magnets consist of ferromagnetic materials whose atomic spines, i.e. elemental magnets, are aligned in parallel by certain processes.
Orientation can be carried out, for example, during the cooling of molten ferromagnetic materials. The ancient Greeks had such stones near Magnesia, a city that bears the name of magnetism. In addition to natural processes, permanent magnets can also be produced artificially.
In artificial manufacture, ferromagnetic metals, often alloys, are artificially magnetized by strong magnetic fields. Magnets made by this process exhibit hysteresis, which provides an asymmetry by enlarging and then reducing the external magnetic field. In atomic spin alignment, this is stabilized by an exchange interaction, giving already magnetized materials different properties. Hysteria is also established here.
If the external magnetic field is switched off, the residual energy still remains in the magnet due to the hysteresis, which makes it a permanent magnet.
The different types of permanent magnets
Magnets have different types depending on geometry, properties and material. In the case of geometries, for example, disc magnets, bar magnets (cylindrical, but longer), block magnets, cube magnets, hook magnets (also available in color), spherical magnets, ring magnets and other special shapes are available.
The properties also offer a multitude of possibilities, resulting from the requirements of a magnet's applications. For example, there are waterproof magnets, which are coated for this purpose. Another example is adhesive magnets, which have an adhesive strip to stick to. Mounting options also include magnets designed for screwing or sewing.
Permanent magnets cannot stop working, as their name indicates they are permanent. It would only be possible by disturbing the orientation of the elementary magnets by external forces such as magnetic fields or heat, this could be done. Permanent magnets can also be magnetized again to restore magnetic forces. In extreme cases, it could damage the material. To avoid damage, a maximum operating temperature is prescribed for permanent magnets. When a specific material temperature, also called Curie temperature, is exceeded, the permanent magnets are completely demagnetized.
Applications of Magnets
The applications of magnets can be very diverse. For example, magnets are used in assembly robots. An assembly robot, which is screwed on, can be equipped with a rotating magnetic clamp, so that the screws can be safely picked up and screwed on.