How is the magnet made out?
Iron, cobalt, nickel or ferrite and other ferromagnetic materials are different, it's internal electron spin can spontaneously arranged in a small area to form a spontaneous magnetization area, this spontaneous magnetization area is called magnetic domain. Ferromagnetic material magnetization, the internal magnetic domain neatly, aligned in the same direction, so that magnetic strengthening, it constitutes a magnet. Magnet iron absorption process is the process of magnetization, magnetized iron and magnet have different attraction between the polarity, iron firmly with the magnet "stick" together.
The natural magnet is ferroferric oxide, and the artificial magnet is usually steel. After the magnetization of the magnet will remain after the magnetic The general term refers to the natural permanent magnet is not only ferrite (iron oxide), as well as iron cobalt-nickel alloy, rare earth alloy of iron and other permanent magnetic materials, such as aluminum nickel Cobalt, NdFeB, these are also very common, magnetic very strong, these substances can be magnetic field constant magnetic field magnetization, and magnetization itself has a magnetic and does not disappear. The composition of artificial magnets is based on the magnetization of various metals, according to need. Magnet close to (touch) magnetic material, the material near the end of induction into a different name, and the other end of the name of the same name.
Classification of magnets
A. Temporary (soft) magnets
A. Meaning: magnetic short, when the magnet removed after the magnetic disappeared. Examples: nails, wrought iron
B. Permanent (hard) magnets
A. Meaning: After magnetization, long-term retention of magnetic. Example: nails
According to the above information is summarized as follows: According to the principle of electromagnetic induction, a strong current can produce a strong magnetic field, the use of a strong magnetic field to ferromagnetic material magnetization, and because of different substances magnetization characteristics are not the same, some materials easy magnetization, Magnetic (loss of magnetic), can be a long time to retain the magnetic. Magnetizing this material produces a magnet. Magnetizing the hard magnet with a magnetizer.
According to the principle of electromagnetic induction, the current can produce a magnetic field, the use of strong magnetic field will be hard magnetic material is generally referred to as the magnetic material of the magnet, in fact, several different things: the most common magnets, such as general speaker magnet, Magnetic oxygen magnet. They are iron slabs (iron oxides in the form of flakes) which are detached from the surface of the billet during the hot rolling of the steel plant and are subjected to impurity removal and pulverization followed by the addition of a small amount of other substances into a steel mold for compression molding , And then in the reducing electric furnace (hydrogen) sintering, so that part of the oxide reduction was ferrite, cooling, and then into the exciter in the magnetization produced.
More than they are more high-grade magnet: Magnet is the real steel, in addition to iron composition, the main content of nickel higher. It is generally smelted with intermediate frequency electric furnace (only ten kilograms per furnace), casting molding, because of its accuracy requirements of some of the plane, generally have to use grinding machine grinding. And then magnetization, a product. All kinds of electricity meter used to measure the magnets. More advanced magnetic materials, is NdFeB magnetic materials. They are substances containing rare earth elements neodymium, iron and boron. Production is the method of production of cemented carbide: After milling - mixing - molding - sintering - finishing - from magnetization. This magnetic field of the highest strength, the best performance, the most expensive. Is the defense industry and precision equipment will be used. The electronic surface of the stepper motor is the rotor. Ah, the magnetic levitation train must use this kind of magnetic material. Ferrite permanent magnetic materials are: strontium - ferrite permanent magnet materials and barium - ferrite permanent magnetic materials, there are isotropic and anisotropic points, speaker magnet commonly used ferrite permanent magnet materials ; Metal permanent magnet materials are mainly aluminum-nickel-cobalt permanent magnet materials and rare earth permanent magnetic materials. Rare earth permanent magnetic material is divided into: SmCo permanent magnet materials and NdFeB permanent magnetic materials. Rare earth permanent magnet material is made by powder metallurgy process. Magnetic strength? I do not find persuasive information.
Magnet classification too much, I am here simply to say:
There are two main types of magnetic materials: the first is permanent magnetic materials (also known as hard): the material itself has the characteristics of magnetic preservation. The second is the soft magnetic (also known as electromagnet): the need for external power to generate magnetic, we are talking about the magnet, generally refers to the permanent magnet material.
There are two major categories of permanent magnetic materials: The first category is: alloy permanent magnet materials, including rare earth permanent magnet materials (NdFeB Nd2Fe14B), SmCo (SmCo), neodymium nickel cobalt (NdNiCO). The second category is: Ferrite permanent magnet material (Ferrite) according to different production processes are divided into: sintered ferrite (Sintered Ferrite), bonded ferrite (rubber magnetic Rubber), injection ferrite (Zhusu Ferrite) ), These three processes based on the different orientation of the magnetocrystalline and are divided into isotropic and anisotropic magnets.
