Types of Magnetic Materials
Hard magnets can be divided into four categories, arranged in order of magnetic force. They are ferrite, AlNiCo, samarium cobalt and neodymium iron boron. The following are the overall characteristics of these four magnets, which will help us choose what kind of magnetic material is needed?
Ferrite Magnet
Ferrite magnets are composed of strontium or barium ferrite. They have relatively high magnetism and have good heat resistance, corrosion resistance and demagnetization resistance. Because they are the cheapest, they are currently the most widely used magnets. Mainly used in motors and generators, magnetic adsorption and fixation, sensors and detectors, magnetic medical and magnetic therapy products, magnetic storage devices and other fields.
Characteristics
⚫ High Temperature Resistance (300 ℃）
⚫ Corrosion Resistance
⚫ Lowest Cost and Commercial
Alnico Magnet
Alnico magnet is composed of three materials: aluminum, nickel and cobalt. It has extremely excellent high temperature resistance (550℃), high remanence rate and corrosion resistance. It can be produced by casting or powder metallurgy. It is mainly used In various high-precision and high-reliability instruments and meters, as well as in high-temperature environments.
Characteristics
⚫ Excellent High Temperature ( 550℃）
⚫ High Remanence
⚫ Corrosion Resistance
Samarium Cobalt Magnet
It is a rare earth magnet, which is composed of samarium, cobalt and some other rare earth materials. It has high magnetic energy product and is resistant to high temperatures - the maximum temperature is 350℃, and there is no limit to negative temperature. When the operating temperature is above 180℃, its maximum magnetic energy product , the coercivity, temperature stability and chemical stability exceed that of NdFeB materials, and it also has strong corrosion resistance and oxidation resistance; the disadvantage is that it is fragile, so special attention must be paid to protection during use to avoid being damaged Impact or pressure to prevent breakage. They are widely used in aerospace, national defense industry, microwave devices, communications, medical equipment, instruments, meters, various magnetic transmission devices, sensors, magnetic processors, motors and other products that require high temperature resistance.
Characteristics
⚫ High Temperature Resistance( 550℃）
⚫ High Magnetic Energy
⚫ High Temperature and Chemical Stability
⚫ Corrosion Resistance
⚫ Easy Cracking and Chipping
Neodymium Magnet
NdFeB is mainly composed of rare earth elements neodymium, iron and boron. It has extremely high magnetic properties, including high magnetic energy product, strong magnetic field and high coercive force. It is the magnet with the strongest magnetic properties currently known. One of the materials. NdFeB magnets are widely used in electronics, electric machinery, medical equipment, toys, packaging, hardware machinery, aerospace and other fields because of their excellent magnetic properties. Common applications include permanent magnet motors, speakers, magnetic separators, computer disk drives, magnetic resonance imaging equipment instrumentation, etc. The disadvantage is that the operating temperature is relatively low. Under continuous high temperature conditions, demagnetization will occur. The normal operating temperature is 80°C, and the maximum temperature currently used for high-temperature grades is about 150°C.
Characteristics
⚫ Strongest Magnetic Property
⚫ High Magnetic Energy and Strong Magnetic Field
⚫ High Temperature, easy demagnetization
⚫ Weak Corrosion Resistance, need to do
⚫ Relatively Easy Cracking and Chipping
Material Comparisons
Magnetic force
Neodymium Magnet> SmCo Magnet > AlNiCu Magnet>Ferrite Magnet
In view of the fact that NdFeB magnet has the strongest magnetic force and relatively low material cost, they are currently the most widely used magnet; The SmCo magnet has high coercive force ,high temperature resistance (maximum temperature 350 degrees) and good electrical conductivity. It is widely used in electronics, chemical industry, electric power and other fields!
High Temperature Resistance
AlNiCo Magnet (550 °C)>Smco Magnet Pot (350 °C)>Ferrite Magnet Pot (300 °C)>Neodymium Magnet Pot （80-200 °C）
Because magnets will demagnetize when heated, the working temperature is one of the important considerations when choosing magnet pots. Especially in high-heat working environments, The high-temperature resistant magnetic pot should be chose.
