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德语High-Temperature Samarium Cobalt Magnet is a series of rare earth magnets made of samarium and cobalt that are designed for operation at extremely high temperatures while maintaining their magnetic qualities over a wide temperature range. Their maximum energy product increases with rising temperature (up to 33 MG*Oe), but flux density remains relatively constant, changing less than 5% per degree Celsius change in temperature. Samarium-cobalt magnets are fragile enough that they may crack or break under stress; thus making them unsuitable for dynamic applications where vibration or shock conditions exist.
These high-temperature samarium-cobalt permanent magnets come in both sintered and bonded variants to meet application-specific requirements. Sintered versions are most frequently utilized and offer excellent performance in both low-temperature and high-temperature environments. Samarium cobalt alloy is typically melted under inert gas (usually argon) at temperatures reaching 1200degF before it's cast into ingots for cooling. When these have been set down they are then ground into powder particles before being baked at temperatures between 1150-1250degF in the sintering process which creates a dense mass of magnet material which can then be pressed into shapes for final shapes.
Due to their ability to withstand extreme temperatures and retain magnetism well, samarium-cobalt rare-earth magnets have found widespread application across military, aerospace, and other high-tech industries. Their special magnetic properties also make them desirable components in manufacturing medical devices, industrial machines, and motors.
In 1995, the United States Air Force and other branches of the Department of Defense requested magnets capable of withstanding temperatures greater than 400degF without diminishing performance, leading to ultra-high-temperature samarium cobalt magnets with higher operating temperatures than conventional Sm2Co17 grades.
Samarium-cobalt magnets share similar traits as other rare-earth magnets in that they possess high coercivity and resistance to demagnetization, thanks to domain wall pinning properties where impurities in its crystal structure prevent the reversal of magnetic field lines.
Though samarium-cobalt is less strong than its rival neodymium, it offers superior corrosion protection and thermal stability at higher temperatures. Furthermore, samarium-cobalt is more widely available compared to rare earth elements like neodymium which require expensive extraction processes for extraction.
SmCo magnets offer an effective alternative to alnico magnets such as aluminium-cobalt which are more widely used but do not maintain the same magnetic properties in elevated temperatures. Furthermore, unlike ferrite magnets which may succumb to oxidation and decomposition in high-temperature environments, samarium-cobalt and other rare-earth materials do not suffer oxidation or decomposition when heated above certain thresholds.
Due to their high operating temperature, rare-earth magnets must be handled carefully to avoid damage or cracking. Furthermore, it is vital that they do not come into close proximity with other magnetic objects as this could cause interference and potentially harm nearby components. Furthermore, gloves should always be worn when handling such magnets to protect from sharp edges or surfaces that may puncture through.
550 ℃ High Temperature Samarium Cobalt Magnet
