How To Understand The Performance Curve Of Strong Magnets

How to understand the performance curve of strong magnets? The value of the reverse magnetic field strength required to reduce the magnetic induction intensity to zero is called the magnetic induction coercive force (Hcb) when the magnet after the saturation magnetization of the powerful magnet technology is reversely magnetized. However, the magnetization of the magnet is not zero at this time, but the applied reverse magnetic field and the magnetization of the magnet cancel each other out. (The external magnetic induction intensity is zero) If the external magnetic field is canceled at this time, the magnet still has certain magnetic properties. The coercivity of NdFeB is generally above 11000Oe.

When a magnet is magnetized by an external magnetic field in a closed-circuit environment to the technical saturation, the external magnetic field is cancelled. At this time, the magnetic induction intensity of the magnet is called remanence. It represents the maximum magnetic flux value that the magnet can provide. It can be seen from the demagnetization curve that it corresponds to the situation when the air gap is zero, so the magnetic induction intensity of the magnet in the actual magnetic circuit is smaller than the remanence. NdFeB is a practical permanent magnet material with high Br found today.

The strength of the reverse magnetic field applied by a strong magnet to reduce the magnetization of the magnet to zero is called the intrinsic coercive force. Intrinsic coercivity is a physical quantity that measures the magnet's ability to resist demagnetization. If the applied magnetic field is equal to the intrinsic coercive force of the magnet, the magnetism of the magnet will be basically eliminated. The Hcj of NdFeB will decrease with the increase of temperature, so the grade with high Hcj should be selected when it needs to work in a high temperature environment.