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Soft magnetic alloy and solenoid valve core material

Soft magnetic alloy and solenoid valve core material
The powder prepared by this method has high purity, good uniformity and small particle size, especially for multi-component systems, the uniformity can reach the level of molecules or atoms. The sintering temperature is lower than the high temperature solid phase reaction temperature, and the grain size increases with increasing temperature and time. The complete crystallization temperature is about 750°C. Compared with the coprecipitation method, the nanopowder synthesized by this method only agglomerates when sintered, and is completely crystallized at a low temperature (700-800°C). This can save energy, avoid the introduction of impurities from the reactor due to high sintering temperature, and easy to form part of the gel before burning, has a larger surface area, which is conducive to the formation of products. It is a better method for preparing ultrafine powder.
3 Hydrothermal method The hydrothermal method is also a new synthesis method for preparing ultrafine powder that has been developed in the past 10 years. This method uses water as a solvent, and at a certain temperature and pressure, a method for making a substance chemically react in a solution. This method can realize the doping of inorganic functional materials, and this method can realize the doping of polyvalent ions. These characteristics are new materials for research. Provides favorable conditions. In the hydrothermal reaction, the formation of fine powder crystallites undergoes a dissolution-crystallization process. The prepared fine powder crystals are small in size, uniform in particle size, and do not require high temperature calcination pretreatment. The synthesis temperature is approximately 900°C, and the crystals formed are More complete, high purity, and high activity. Studies have shown that the hydrothermal reaction temperature, time and other factors have a great influence on product purity, particles, and magnetic properties, and the prepared fine powder grains are generally only tens of nanometers.
4 Supercritical method The supercritical method refers to a method of preparing fine powder under supercritical conditions in a hydrothermal reactor using organic solvents instead of water as a solvent. The disappearance of the liquid phase during the reaction is more conducive to the uniform growth and crystallization of the particles in the system. This method is superior to the hydrothermal method and is a further worthy research method. The powder prepared by the supercritical fluid drying method has a uniform particle size distribution, complete crystals, a small specific surface energy, and is not easily agglomerated.
2.1.3 Development trend of soft magnetic alloys In recent years, scholars at home and abroad have conducted effective and new explorations on magnetic materials. Their key researches and applications are mainly focused on the following aspects:
1. Ferrite wave absorbing material Due to the rapid development of science and technology, the application of ferrite as a wave absorbing material in the stealth technology of weapons and information leakage prevention technology in electronic computers, as well as in the thermal effects in biology, is particularly important. In recent years, researchers have mainly focused on the research of composite ferrite materials and nano-sized ferrites to control their electromagnetic parameters. Ferrite nano-magnetic materials are used as microwave absorbers, and nano-particles have a larger specific surface area than conventional coarse powders. 3-4 orders of magnitude, high absorption rate, on the one hand, it can absorb the free molecules in the space or other molecules in the medium are connected together through bonding, resulting in an anisotropic change. On the other hand, in the microwave field, the movement of active atoms and electrons is intensified, which promotes magnetization and eventually converts electromagnetic energy into heat energy, thereby increasing the absorbing ability of the absorber.
2, electromagnetic valve core material in the application of information storage. Information Storage Ferrite Magnetic recording is the use of ferromagnetic media to input, record, store, and output information. Magnetic materials for magnetic recording are classified into two types: Magnetic recording media, which is a material for recording and storing information, is a permanent magnetic material. Magnetic materials Another type of magnetic head material is a sensor material used as input and output information and belongs to a soft magnetic alloy.
3, magnetic fluid Magnetic fluid is a new type of functional material, which consists of magnetic particles, stabilizers (table and active product) and carrier fluid, which shows superior performance over other magnetic materials under magnetic field. So it is widely used. This is a synthetic colloid system consisting of a colloidal magnetic microparticle (magnetite) dispersed in a continuous carrier fluid with the aid of a surfactant. The diameter of the magnetic particles is approximately 10 mm. The magnetic fluid integrates the magnetizability of the solid and the fluidity of the liquid. Under the action of the magnetic field, the magnetic fluid can be magnetized and exhibit superparamagnetism. Magnetic fluids have a wide range of applications in the field of biomedicine. Magnetic drug carriers developed in recent years are highly concerned with both domestic and foreign technologies.
4 Green Materials, Low Carbon and Energy Saving With the convening of the 2010 World Expo. The new economic model based on low energy consumption, low pollution, and low emissions - the arrival of the era of low carbon economy, sustained low carbon and green economy, will be the general trend of future world development. This is a new energy, environmental protection, energy saving and other emerging The industry will bring huge investment and development opportunities in the medium and long term. The low-carbon economy involves a wide range of industrial and management fields, and is also closely related to the development of magnetic materials. It will also be an important direction for the development of new high-tech magnetic material applications and markets in the future.
Soft magnetic alloy products now account for 22% of high-tech applications such as digital communications, electromagnetic compatibility (EMC), radio frequency broadband, electromagnetic interference (EMI), high-definition display, and automotive electronics. The application of traditional middle and low-end products accounted for 78%, such as televisions, power adapters, electronic ballasts, ordinary switching power transformers, antenna rods. Overall, the performance of China's ferrite magnets is still the majority of the middle and low, although the output is highest in the world, but the output value is not ideal. At present, the total output value of magnetic materials in China is about 26.5 billion yuan, the output value of permanent magnet ferrite is 6.2 billion yuan, the average price is 15,000 yuan per ton; the output value of solenoid valve iron core material is 9.3 billion yuan, the average price is 31,000 yuan per ton, and the rest are Cobalt magnets, NdFeB magnets and metal magnets accounted for 11 billion yuan in the market.
The development trend of electromagnetic valve iron core material: 1. The rise of labor and energy cost is a trend; 2. It is still inevitable that the price of raw materials continues to rise in the fluctuation; 3. The export of magnetic products and electronic components will slowly recover in the twists and turns 4. The domestic downstream The fierce competition of users and price war will inevitably push down the price of magnetic material companies, and the profit will gradually decline. 5. The manufacturing enterprises with no production scale and popular middle- and low-grade magnetic materials will survive hard work.
6. The enterprises with cost advantages and technological advantages will be well-developed 7. The overall level of research, development and production of magnetic materials in China will be aligned with the international advanced level, and the magnetic material producing countries will move forward toward becoming stronger countries.

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