Since the advent of NdFeB permanent magnet materials, it has attracted much attention because of its superior magnetic properties. We generally use remanence, coercive force and maximum energy product to measure the performance of magnetic materials.

Remanence Br
If a magnet is compared to a sponge, then the remanence is like a sponge absorbing water and absorbing saturation, and the magnetic value of the magnet is displayed at this time. It refers to the magnetic induction intensity when the magnet is magnetized by an external magnetic field in a closed-circuit environment until the technology is saturated and the external magnetic field is removed.

Coercive force Hcb & Intrinsic coercive force Hcj
Absorb the maximum amount of water in the sponge, then press the water out until no water remains in the sponge. The pressure used is like coercive force. It is the reverse magnetic field intensity value required to reduce the magnetic induction intensity to zero when the magnet is reversely magnetized. But at this time, the magnetization of the magnet is not zero, but the added reverse magnetic field and the magnetization of the magnet cancel each other out. At this time, if the external magnetic field is canceled, the magnet still has certain magnetic properties. Intrinsic coercive force is the strength of the opposing magnetic field required to reduce the magnetization of a magnet to zero.

Maximum energy product (BH)max
The sponge is full of water, and the total amount of water inside can be understood as the maximum magnetic energy product. It represents the magnetic energy density established in the two magnetic pole spaces of the magnet, that is, the static magnetostatic energy per unit volume of the air gap, which is the maximum value of the product of B and H, and its size directly indicates the performance of the magnet.