Ferrite magnet is a metal oxide with ferromagnetism. In terms of electrical characteristics, the resistivity of ferrite is much larger than that of metal and alloy magnetic materials, and it also has higher dielectric properties. The magnetic properties of ferrite also show high permeability at high frequencies.
Therefore, ferrite has become a non-metallic magnetic material widely used in the field of high frequency and weak current. It is a non-metallic magnetic material, which is a composite oxide (or ferrite) of magnetic ferric oxide and one or more other metal oxides. The magnetic force is usually 800-1000 Gauss, which is often used in speakers, speakers and other equipment.
The advantages of neodymium iron boron magnets are high cost performance and good mechanical properties; the shortcomings are that the Curie temperature is low, the temperature characteristics are poor, and they are easy to pulverize and corrode. The chemical composition and surface treatment must be adjusted to make it Improvements can meet the requirements of practical applications.
NdFeB belongs to the third generation of rare earth permanent magnet materials. It has the characteristics of small size, light weight and strong magnetism. It is currently a magnet with good performance and price ratio and is known as the magnet king in the field of magnetism. The advantages of high energy density make NdFeB permanent magnet materials widely used in modern industry and electronic technology. In the state of bare magnetism, the magnetic force can reach about 3500 Gauss.
Magnet magnetic shielding is widely used in our daily life. For example: motor housing, electric meter housing, electric cabinet, horn speaker, etc., all have the function of shielding the magnetic field and focusing the magnetic field.
We commonly use shielding materials: iron sheet, steel plate, cast iron, paramagnetic materials, iron powder cloth, non-magnetic magnets and other soft magnetic materials.
Shielded magnetic field: permanent magnetic field, instantaneous magnetic field, electric wave magnetic field, magnetic radiation magnetic field, powerful magnet shielding, neodymium iron boron magnetic field, current surrounding magnet, electric short-circuit magnetic field, magnet air transport packaging, etc.
The principle of magnetic field shielding: magnetism has N pole and S pole. N and S are connected to a line of magnetic force that cannot be seen with the naked eye. When we shield the magnetic field, we use ferromagnetic material to reflect the magnetic field line to make it the shortest The route creates a loop, so that the effect of shielding part of the magnetic lines of force is achieved, and the space outside the shielding reduces the effect of magnetic lines of force.
The practical application of magnetic isolation: 0-distance shielding and air-distance shielding, 0-distance shielding is the most commonly used, for example, a motor belongs to a 0-distance shielding. When the current passes through the coil, the magnetic field generated by the motor will not leak the magnetic field .