Substances are mostly made of molecules, molecules are made of atoms, atomic nuclei and electrons in turn, constituted. Atomic internal electronic stop rotation, and rotation around the nucleus. Both the electron motion occurs magnetism. However, in most substances, the direction of motion of the electron vary, mess, magnetic effects cancel each other. Thus, most of the material under normal circumstances, does not exhibit magnetic properties.
Iron, cobalt, nickel or ferrite ferromagnetic substances have not the same, its internal electron spin can consciously put up in a small area, forming a conscious magnetized area, this area is called magnetic magnetization conscious domains. Magnetization of ferromagnetic substances, the internal magnetic domain neatly put together in the same direction to make magnetic strengthened constitute a magnet. That is the process of absorption of iron magnet is magnetized iron process, the magnetized iron and the magnet is not the same attraction occurs between the polar, iron and the magnet on firmly "stick" together.
Natural magnet is iron oxide, which is usually artificial magnet steel. After a magnetized steel will always retain the magnetic properties.
Natural permanent magnets usually refers not only ferrite (c Fe3O4), as well as iron-cobalt-nickel alloy, iron and various rare earth permanent magnetic materials and other alloys, such as aluminum, nickel and cobalt, SmCo, NdFeB these are also a lot to see, very strong magnetic properties, these substances can be magnetized by the magnetic field constant magnetic field, and magnetic magnetized itself and not disappear. Artificial magnet composition according to various metals are magnetized function, according to demand.
Guangdong magnet according to the production technology is not as divided into the following three types:
(1) sintered NdFeB (SinteredNdFeB) - (NdFeB permanent magnets after airflow grinding powder from exercise coercive force value is high, and has a very high magnetic function, the maximum energy product (BHmax ) higher than the ferrite (ferrite) more than 10 times its own mechanical function is also very good, can not the same shape cutting and drilling. high maximum operating temperature up to 200 degrees of functional goods. Because of its substance content simple cause corrosion, so according to different requests must be on the look not the same coating. (such as plating Zn, Ni, Au, Epoxy, etc.). very strong and brittle, have high resistance to demagnetization, high cost / feature ratio does not apply to high operating temperatures);
(2) bonded NdFeB (BondedNdFeB) - is NdFeB Bonded NdFeB powder and resin, plastic or low melting point metal binder such uniformly mixed, and then tightening, kneading or injection molding and other methods composite made of NdFeB permanent magnets. Forming a commodity, no secondary processing, can be directly made into various shapes clutter. Bonded NdFeB all directions have a magnetic, can be processed into molds and injection mold NdFeB austerity. High precision, magnetic features excellent corrosion resistance, good temperature stability.
(3) Injection NdFeB (ZhusuNdFeB) - there is a high degree of precision, simple shapes made of anisotropic messy thin-walled or thin ring magnets
2. sintered ferrite (SinteredFerrite) of the main raw material and contains BaFe12O19 SrFe12O19, according to the orientation of the magnetic crystal divided into different isotropic and anisotropic magnetic properties. Because of its low price and moderate magnetic functions now the most widely used and become a magnet. The annual output of 300 tons or more. Ferrite magnets are manufactured through ceramic technology law, texture is also more robust, it is a brittle materials, since ferrite magnets have good temperature resistance and low price, has become the most widely used permanent magnets.
3. Rubber magnet (RubberMagnet) is a series of magnetic ferrite, ferrite powder bonded by a synthetic rubber compound and by extrusion molding, calendar molding, injection molding technology and made of a flexible, resilient and can distort the magnet. Processed into strips, roll, sheet and various shapes clutter. The rubber magnet powder (SrO6Fe2O3), polyethylene (CPE) and other additives (EBSO, DOP) and the like, by extrusion, calendering made of. Rubber Magnets can be of the same sex or the opposite sex, which is made of ferrite powder, CPE, and some trace elements, can be bent, you can twist, can be rolled. It can be used without further machining, it is possible according to the required scale trim shape, rubber magnet can request re-PVC, gum according to the customer, the UV oil. Its energy product between 0.60 to 1.50MGOe. Art rubber Magnets: refrigerator, notice message frame, fixed to the object? Metal body to serve as advertising and other fasteners used in toys, educational equipment, switches and sensors diskette. First used in micro motors, refrigerator, disinfection cabinet, kitchen cabinets, toys, stationery, advertising and other professional.
4. Alnico (AlNiCo) is the first developed out of a permanent magnetic materials, is an alloy of aluminum, nickel, cobalt, iron and other trace metal elements. According to the production technology is not the same into sintered Alnico (SinteredAlNiCo) and forged aluminum-nickel-cobalt (CastAlNiCo). Goods are mostly round and square shapes. Forging technology can be processed into different dimensions and shapes; compared with forging technology, the sintered product is limited to a small scale, the scale of its production out of rough trade rough forging better than Gongyi, slightly lower than the magnetic function to forge goods, but better workability. In the permanent capital guess, forging Alnico Magnets has the lowest reversible temperature coefficient, operating temperature up to 600 degrees Celsius. Alnico Magnets commodity widely used in various instruments and other fields of use.
5. samarium cobalt (SmCo) according to different components into SmCo5 and Sm2Co17, respectively Zi Zi generation and second-generation rare earth permanent magnet materials. Because of its raw materials are scarce, expensive and limited it to carry out. Samarium cobalt (SmCo) as the second generation of rare earth permanent magnet, not only has a high energy product (14-28MGOe) and reliable coercive force, and exhibits good temperature characteristics in rare earth permanent magnet series. Compared with NdFeB, samarium cobalt is more suitable for operation in high temperature environments.