Neodymium magnets, a member of the rare earth magnet family, are well known for being the strongest magnets available. However, compared to samarium cobalt rare earth magnets, neo magnets do not have the same tolerance for high temperatures. Samarium cobalt magnets have a working temperature of up to 300°C, but standard neodymiums only have a working temperature of up to 80°C, at which point they begin to lose their magnetic strength. Because samarium cobalt magnets are also members of the rare earth magnet family, they are still very strong, and significantly stronger than ceramic and alnico magnets. However, samarium cobalt magnets cannot deliver the same strength as neo magnets. To address the need for neo magnets in applications with maximum temperatures exceeding 80°C, high temperature neodymium magnets have been developed.
It should not be implied that neodymium magnets are easily demagnetized, as they (like other rare earth magnets) have an excellent resistance to demagnetization. If a neo magnet is dropped or exposed to other magnets, it will not lose its magnetic strength. However, if a neodymium magnet is heated above its Curie temperature, it will completely lose its magnetization. Additionally, as a neodymium magnet is heated to temperatures approaching its Curie temperature, it will gradually lose magnetization and become progressively weaker as temperatures increase. Neodymium magnets also lose their resistance to demagnetization as they are heated above room temperature.
High Temperature Neodymium Magnets vs. Samarium Cobalt Magnets
Samarium cobalt magnets, with their higher working temperature, are commonly used in applications where neo magnets are unable to tolerate higher temperatures. However, samarium cobalt magnets do not always meet the strength requirements demanded by certain applications. To resolve this issue, high temperature neodymium magnets have been developed.
High temperature neodymium magnets, available at Bunting-DuBois, can safely be used at operating temperatures up to 150°C, with some special grades able to operate in excess of 200°C. There are many applications where high temperature neodymiums may be desired. Neo magnets used in motors, automotive, and aerospace applications may be required to tolerate higher temperatures. Additionally, neodymium magnets may be utilized in industrial applications such as welding clamps, oil filters, and simple holding applications. When there is any concern at all about a magnet being exposed to higher temperatures, it is recommended to err on the side of caution and select magnets designed to tolerate high temperatures.
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