The Rare Earth Permanent Magnetic Material, Rare earth permanent magnet, samarium cobalt (SmCo) permanent magnet, neodymium iron boron permanent magnet (NdFeB), Sintered magnets
Rare earth permanent magnetic material is the samarium, neodymium rare earth metal and transition metal (such as cobalt, iron and so on) the composition of the alloy, powder metallurgy method of pressure sintering, a magnetic material by magnetic field magnetization prepared.
Rare earth permanent magnet consists of samarium cobalt (SmCo) permanent magnet and neodymium iron boron permanent magnet (NdFeB) , the magnetic energy of SmCo magnet product between 15 ~ 30MGOe, NdFeB magnetic energy of the permanent magnet product between 27 ~ 50MGOe, known as the “quot;king of permanent magnet”quot;, is currently the highest permanent magnetic materials magnetic. Samarium cobalt permanent magnets, despite its excellent magnetic properties, but contains reserves of rare metal samarium and scarce, expensive strategic metal cobalt, therefore, its development was restricted. Development of rare earth permanent magnet industry in China began in the late 60’s, the leading product was samarium-cobalt permanent magnet, the samarium-cobalt permanent magnets worldwide sales of 630 tons, China’s 90.5 tons (including SmCo powder), mainly used for military technology. With the development of computer, communication, industry, rare earth permanent magnet especially NdFeB permanent magnet industry has been rapid development.
Rare earth permanent magnetic materials is now known as the highest performance to a permanent magnetic materials, magnetic than nineteenth Century for the use of the magnet can be 100 times more, than the ferrite, alnico vastly superior performance, can also twice as high than magnetic cobalt platinum alloy expensive. Due to the use of rare earth permanent magnetic materials, not only to promote the development of permanent magnetic device to miniaturization, improve product performance, and to produce some special devices, so the rare earth permanent magnetic materials appeared, immediately aroused great attention, is developing rapidly. The performance of our country to develop and produce all kinds of rare earth permanent magnetic materials has been close to or reached the international advanced level.
Now rare earth permanent magnetic materials has become an important material for electronic technology in communication, used in satellite, radar and other aspects of the traveling wave tube, a circulator and a miniature motor, miniature tape recorder, aviation equipment, electronic watches, seismic instrument and other electronic instruments. The rare earth permanent magnet is widely used in automobile, household appliances, electronic instruments, magnetic resonance imaging, audio equipment, micro motor, mobile phone etc.. In terms of medical treatment, use of rare earth permanent magnetic materials “quot;magnetic acupoint therapy”quot;, the effect is greatly improved, thereby promoting the “quot;rapid promotion magnetic acupoint therapy”quot;. Applications in various fields of rare earth, rare earth permanent magnet material is one of the fastest growing. It not only to the development of rare earth industry has brought enormous impetus, also produced a profound influence on many related industries.
Classification two, rare earth permanent magnetic material
1 rare earth permanent magnetic materials, including rare-earth cobalt (1-5) permanent magnetic material of rare earth cobalt (SmCo5 and 2-17) permanent magnetic material Sm2Co17 two categories.
2 rare earth neodymium magnets, NdFeB permanent magnetic material.
3 rare-earth iron nitrogen (RE-Fe-N) or rare earth iron carbon (RE-Fe-C) permanent magnetic material.
Three, the rare earth permanent magnetic material preparation process classification
1 powder metallurgy sintering process to prepare;
2 reduction diffusion milling or hydrogen crushing processing sintered magnet powder and powder metallurgy sintering process to prepare;
3 rapid solidification or hydrogen crushed powder (HDDR), bonded magnet powder moulding bonding process;
4 rapid solidification or hydrogen breaking (HDDR) powder injection process for preparing the injection magnet;
5 rapid solidification or hydrogen breaking (HDDR) powder prepared by hot pressing hot-pressed magnets;
6 using hot-pressed magnets and anisotropic thermal deformation pressure preparation process of deformation pressure magnet;
7 thermal deformation pressure magnet made into powder, then the molding or injection method preparation of anisotropic bonded magnets.
The main application of four, rare earth permanent magnetic material
Effect of the permanent magnet is essential to generate a constant in a certain space magnetic field, the magnetic field does not require any external power supply. There are a lot of signs or permanent magnet material parameters, the most important is the maximum energy product (BH) max, maximum energy product more, external magnetic field produced by the material energy per unit volume is bigger. The maximum magnetic energy product of NdFeB permanent magnetic material product has reached: 50MGOe. Because of the characteristics of high energy rare-earth permanent magnetic material product and high coercive force, excellent, permanent magnet application has to bring revolutionary change, rare earth permanent magnet material is mainly used in the following aspects:
Rare-earth permanent magnet motor, mean field will cause revolutionary change. This is because the rare earth permanent magnet no excitation loss, no fever, many motor has made of it. Because of rare earth permanent magnet motor without excitation coil and core, magnet volume than the original magnetic field is very small occupied space, no loss, no heating, so as to get the same output power of the volume, the weight can be reduced by more than 30%, or the same volume, weight, large output power by 50%.
Permanent magnet motor, especially the micro motor, the annual production of about hundreds of millions of the world, are mainly used in automobile, office automation equipment and household appliances. The use of multiple high performance ferrite and rare-earth permanent magnet.
The next largest market for rare earth permanent magnet motor will be one of the automotive industry. Neodymium iron boron permanent magnetic material with excellent performance, used in the manufacture of motor, can realize the auto motor “quot;neodymium iron boron”quot;. In the car, only by a small motor, to reduce vehicle weight, increase comfort, increase safety, reduce exhaust emissions, improve the overall performance of the car, is currently the largest amount of start motor. Motor vehicle is an indispensable component, automobile motor number increased year by year. General Motors has 8 ~ 18, senior car up to 40 to 50 units, with the development of automobile industry, automobile motor demand is huge. The rare earth permanent magnets with high magnetic energy product volume is small, but can be more ferrite power much larger, thus improving the efficiency of electricity. Through the use of rare earth magnets reduce weight and size, can save more fuel and increase design flexibility.
Application of 2 rare earth permanent magnetic materials in medical practice (such as nuclear magnetic resonance etc.)
3 magnetic separator
Separator generally have a permanent magnet and electromagnetic type two kinds, previously, permanent magnet type magnetic separator with ferrite. Rare earth permanent magnet appears, make permanent magnetic separator with various models and types of design and, especially in the high intensity magnetic separator, must use the rare earth permanent magnet.
4 computer and peripheral equipment
Device of rare earth permanent magnetic materials used in the computer is the most disk drive motor (VCM), another is the data output printer motor.
5 kinds of instruments
Use a lot of permanent magnet instrument types, such as magnetoelectric meter, counter etc..
6 speakers and headphones
The speaker and the headset is a permanent magnet traditional applications. The speaker has external magnetic type and magnetic type two kinds, rare earth permanent magnet appears in the same power output and quality, the speaker is very small, the rare earth permanent magnet speakers and headphones have been applied to the senior player.
7 microwave devices
In the field of microwave, microwave tube, have wave tube amplifier needs a stable magnetic field generator or. The main aggregation electronic movement of the rare earth permanent magnet in it.