Characteristic analysis of rare earth permanent magnet sintered ndFeB and samarium cobalt
Permanent magnet motors are widely used, but how many people know the category of permanent magnet materials? The characteristics and advantages of different permanent magnet materials? Selection for different environments and applications? This paper is based on such a starting point, the permanent magnetic materials, especially "NdFeB and Samarium Co" rare earth permanent magnetic, do some characteristics analysis.
Rare earth permanent magnet (samarium cobalt, NdFeB) is the most widely used in air compressor. Most of them are made by sintering technology. At present, about 1/3 of the rare earth permanent magnet materials are used in the permanent magnet motor market.
Rare earth permanent magnet is also known to have the highest comprehensive performance of permanent magnet materials, it is 8 ~ 10 times higher than permanent magnet ferrite, 3 ~ 5 times higher than aluminum nickel-cobalt permanent magnet materials, so it has been widely used.
Sintered NdFeB and samarium cobalt price magnetic contrast
A magnetic material composed of samarium, cobalt, and other metallic rare earth materials by mixing. Contains SMCO5 and SM2CO17. NdFeB (Ne2Fe14B) is a tetragonal crystal made of neodymium, iron and boron.
Before analyzing the characteristics of the two major rare earth permanent magnetic materials, samarium cobalt (SMCO) and NdFeB (NdFeB), we need to understand the following two definitions:
Maximum magnetic energy product: The larger the magnetic energy product, the less magnetic material is needed to produce the same effect. So the bigger the BH, the better
Maximum operating temperature: when the temperature is higher than the magnetic sharp drop, can not work normally. When the temperature falls back to the normal level, part of the magnetism can be restored.
Note: the maximum magnetic energy area of NdFeB is affected by the working temperature, for example, to achieve the maximum working temperature of 200℃, according to the current sintering technology can only achieve the maximum magnetic energy product of 38mGOE.
As can be seen from the above: Samarium cobalt and NdFeB as the two most important rare earth permanent magnet material series, each has its own advantages.
NdFeB magnetism is more excellent, but the magnetic temperature stability is poor, easy to be affected by temperature. Samarium cobalt magnetic energy is also better, the best temperature characteristics, compared with NdFeB can better adapt to high temperature environment
Although the price of samarium cobalt is high, it is more and more loved by air compressor manufacturers and highly praised by customers because of its good stability.