High Temperature Magnet 归档 - HGT Advanced Magnets Co.,Ltd

Export License for Rare Earth Magnets, Dual-use Items

The Impact of China’s Export Control Policies on Rare Earth Magnets

In order to safeguard national security and interests and fulfill international obligations such non-proliferation, China issued the Announcement No. 18 of 2025 of The Ministry of Commerce and The General Administration of Customs of The People’s Republic of China Announcing the decision to implement export control on some medium and heavy rare earth related items on April 4, 2025. According to that announcement, seven rare earth elements (REEs) including samarium (Sm), gadolinium (Gd), terbium (Tb), dysprosium (Dy), lutetium (Lu), scandium… Read More

Permanent Magnet Maximum Working Temperature

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Permanent magnets are widely applied in various motors, sensors/instruments and electronics, their temperatures almost vary more or less during work. These temperature variations are resulted from eddy current effect and/or ambient temperature variation. Due to thermal fluctuation and magnetic domain evolution, a permanent magnet loses some or all magnetic flux when its temperature elevates. Here comes a question, how high temperature can a permanent magnet withstand to work? For a commercial permanent magnet, the upper temperature limit is called maximum… Read More

What are Permanent Magnets Temperature Coefficients α and β?

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A permanent magnet’s magnetic properties change as a variation of temperature. For a permanent magnet, remanence (Br) and intrinsic coercivity (Hcj or Hci) are two major parameters, it is important to consider their changes with corresponding temperature variation at work. In order to describe the relative changes, they are calculated according to the following two formulas: α = [Br(T1)-Br(T2)]/Br(T1)/[ T1-T2]×100 (1) β = [Hcj(T1)-Hcj(T2)]/Hcj(T1)/[T1-T2]×100 … Read More