Are you having trouble finding high temperature resistance magnets that work well in high temperatures? It’s important to know how heat affects magnets to make the right choice.
How Curie Temperature Influences Magnetism
Temperature greatly affects the strength of magnets. Heat usually weakens them, while cold can make them stronger. Knowing the limits of different magnets, including how they withstand temperatures, can help avoid costly mistakes.
Heat vs. Cold: The Magnetic Battle
Cold Strengthens, Heat Weakens: Lower temperatures often make magnets stronger, while higher temperatures make them weaker. They work best at or below room temperature.
Maximum Operating Temperature vs. Curie Temperature: Going past a magnet’s maximum temperature can reduce its strength. Going past the Curie temperature means it loses all magnetism. These temperatures vary by magnet type and grade.
Reversible vs. Irreversible Loss: Cooling a magnet can sometimes restore some lost strength (reversible loss). But, some losses are permanent and can’t be recovered once it overheats. High-temperature magnets are designed to maintain performance even under extreme heat conditions.
Top High-Temperature Resistant Magnets for Applications
Going past a magnet’s Curie temperature means it loses all magnetism. Let’s look at some high temperature magnets that can handle extreme heat conditions.
Comparison Table: High-Temperature Resistant Magnets
Magnet Type Maximum Operating Temperature (℃) Curie Temperature (℃)
Al-Ni-Co 525 800
Ferrite 250 450
Sm-Co 310-400 700-800
Nd-Fe-B 80-260 310-400
This table compares the maximum operating temperatures and Curie temperatures of various high-temperature resistant permanent magnets.
1. Al-Ni-Co Magnet – 525℃
Al-Ni-Co magnets are composed of aluminum, nickel, cobalt, and iron. These magnets possess the highest maximum operating temperature of 525℃, making them suitable for extremely high-temperature environments such as industrial furnaces and high-heat sensors.
Introduced commercially in the 1960s, Al-Ni-Co magnets were gradually replaced by rare earth magnets in the 1980s. However, their robustness and reliability ensure they are still widely used today in applications such as aerospace instruments, military radar systems, automotive sensors, and industrial manufacturing.
Ferrite magnets, also known as ceramic magnets, consist of a large amount of iron oxide mixed with small proportions of other metallic elements. Despite having a relatively lower maximum operating temperature of 250℃, ferrite magnets are popular due to their cost-effectiveness, excellent electrical resistance, and excellent heat resistance. They find extensive applications in household appliances, medical devices, and magnetic resonance imaging (MRI) systems, where moderate temperature resistance and high magnetic stability are essential.
3. Sm-Co Magnet – 310~400℃
Samarium-cobalt (Sm-Co) magnets, a type of permanent magnet, offer strong magnetic power and can operate at temperatures ranging from 310 to 400℃. While they are not as strong as neodymium magnets, their higher temperature ratings make them ideal for high or extremely low-temperature applications, such as satellite systems, microwave communications, and high-performance electric motors. Sm-Co magnets are also known for their excellent resistance to oxidation, corrosion, and demagnetization. Advanced Magnetics Inc. specializes in manufacturing and supplying high-quality samarium-cobalt magnets, catering to industries that demand high thermal stability and durability.
4. Neodymium Magnets (Nd-Fe-B) – 80~260℃
Neodymium-iron-boron (Nd-Fe-B) magnets, commonly known as neodymium magnets, are the strongest commercially available magnets. High temperature neodymium magnets are specialized products engineered for high temperature applications, highlighting their excellent heat resistance and durability. Their working temperature can reach up to 260℃, and they are classified by temperature grades: M (80-100℃), H (100-120℃), SH (120-150℃), UH (150-180℃), and EH (180-260℃).
The magnetic strength of Nd-Fe-B magnets is closely related to ambient temperature changes. Within their working temperature range, they lose approximately 0.11% of their magnetism per 1℃ increase in temperature. This loss is typically reversible upon cooling, unless the temperature exceeds the Curie point, at which irreversible demagnetization occurs. Nd-Fe-B magnets are widely used in wind turbine generators, electric vehicle motors, and consumer electronics, where their superior magnetic properties and moderate temperature resilience are highly valued.
Related article: The Ultimate Guide to Neodymium Magnet
Conclusion
Choosing the right high-temperature resistant magnets that can withstand extreme heat is key for your project. Think about what you need and check the temperatures to ensure they work well. Don’t settle for anything less than the best to get long-lasting results.
For more information, visit Mainrich Magnets. With over 30 years of expertise and a 98+% quality consistency rate, we offer high-quality rare earth magnets at fair prices. Our customer-centric service and adherence to ISO 9001:2015, RoHS, and REACH standards ensure you get the best. Reach out to discover more.
