What is coercivity

The performance parameters of Ndfeb permanent magnet material have two very important parameters coercivity and intrinsic coercivity.

How do we understand coercivity and intrinsic coercivity?

Popular understanding: has been filled with magnetic Ndfeb magnet, its magnetic force down to 0 required force is coercivity. Let's call it Hcd.

Coercivity refers to the magnetic field intensity required to reduce its magnetization to zero after magnetic material has been magnetized to magnetic saturation.

Intrinsic coercivity: The strength of the reversed magnetic field required to reduce the residual magnetization of a magnet to zero, we call this intrinsic coercivity.

When the reverse magnetic field H= Hcb, although the magnetic induction intensity B of the magnet is 0 and the magnet does not display magnetic flux externally, the vector sum of the microscopic magnetic dipole moment inside the magnet is usually not 0, that is to say, the magnetic polarization intensity J of the magnet at this time always maintains a large value in the original direction. Therefore, Hcb is not enough to characterize the intrinsic magnetic properties of magnets. When the reversed magnetic field H increases to a certain value Hcj, the vector sum of the microscopic magnetic dipole moment inside the magnet is 0, and the reversed magnetic field H value is called the intrinsic coercivity Hcj of the material.

Coercivity and intrinsic coercivity are in units of A/m (iso) or Oe (Gauss system of units).

Coercivity represents the ability of magnetic material to resist demagnetization, and demagnetization is the opposite of demagnetization, why has been prompted to resist demagnetization, this is its main role.

According to the value of coercivity, it can be divided into M\H\SH\UH\EH, which means medium, high, high, ultra-high and extremely high coercivity. The corresponding operating temperature is 100 degrees, 120 degrees, 150 degrees, 180 degrees and 200 degrees.