☞What are the main magnetic parameters of the permanent magnets?
Remanence (Br): When permanent magnet is magnetized to saturation, we remove the external magnetic field. The residual magnetic flux density retained in the direction of magnetization is called remanence.
Intrinsic coercive force (Hcj): The intensity of reverse magnetic field required to reduce the residual magnetization strength of magnet to zero is called intrinsic coercive force.
The Maximum magnetic energy product( (BH)max): The maximum magnetic energy product is the maximum product value of the magnetic flux density and magnetic field strength on the demagnetization curve. The greater the value is, the greater the stored magnetic energy in unit volume will be and the better the performance will be.
☞For all of these various permanent magnets, do they have the same magnetic field strength? Which kind of permanent magnet has the strongest magnetic force ? In case they have the identical size and shape, the magnetic field strength from high to low is as the below:
Sintered NdFeB > SmCo > AlNiCo > Hard Ferrite > Flexible magnet.
☞Is it true that the higher the Gauss value of the magnet is, the stronger the magnetic force and absorption force will be ?
No, it's not. Let's make it clear that Gauss value comes out of Gauss meter (also called Teslameter），which indicates the magnetic induction intensity of a certain point on the magnet surface and also means the magnetic flux density at the same place. So Gauss value cannot accurately reflect the objective value of the magnetic force of the whole magnet.
☞Which kind of permanent magnet has the best temperature resistance?
The temperature resistance performance from high to low is AlNiCo > SmCo > Hard Ferrite > NdFeB. Besides, with the continuous improvement of technology, the working temperature of NdFeB can also reach above 200 centigrade degrees.
☞What's the difference between the Curie temperature and the working temperature ？
The Curie temperature indicates the theoretical limit of working temperature of the permanent magnet. While the working temperature indicates that the magnetic performance of the permanent magnet begin to decline at this temperature. In practice, the working temperature is far below than the Curie temperature.
☞What factors affect the cost of the permanent magnets?
The raw material cost: Especially for the rare earth permanent magnets like NdFeB and SmCo, their raw materials are mainly the rare earth metals. The rare earth raw material price fluctuation will cause the changing of the magnet cost. The raw material cost accounts for roughly 70% of the total magnet cost.
