Basic parameter knowledge of magnet

Permanent magnet material:The magnetism of the permanent magnet material does not disappear after being magnetized by an external magnetic field, and can provide a stable magnetic field to the external space. NdFeB permanent magnets are commonly used to measure the following four indicators:
Remanence (Br）The unit is Tesla (T) and Gauss (Gs） 1Gs =0.0001T
When a magnet is magnetized by an external magnetic field in a closed-circuit environment to cancel the external magnetic field after technical saturation, 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 case when the air gap is zero, so the magnetic induction intensity of the magnet in the actual magnetic circuit is less than the remanence. NdFeB is now foundBrHighest practical permanent magnet material.
Magnetic induction coercivity (Hcb）Unit is Ann./Meters (A/m) and Oster (Oe) or1 Oe≈79.6A/m
The value of the reverse magnetic field strength required to reduce the magnetic induction intensity to zero when the magnet after technical saturation magnetization is reversed is called the magnetic induction coercive force (Hcb). However, the magnetization of the magnet is not zero at this time, but the effect of the reverse magnetic field and the magnetization of the magnet cancel each other out. (The external magnetic induction intensity is zero) At this time, if the external magnetic field is withdrawn, the magnet still has certain magnetic properties. The coercivity of NdFeB is generally11000OeAbove.
Intrinsic coercivity (Hcj）Unit is Ann./Meters (A/m) and Oster (Oe）1 Oe≈79.6A/m
The strength of the reverse magnetic field required to reduce the magnetization of the magnet to zero is called the intrinsic coercivity. Intrinsic coercivity is a physical quantity to measure the anti-demagnetization ability of a magnet. If the applied magnetic field is equal to the intrinsic coercivity of the magnet, the magnetism of the magnet will be basically eliminated. NdFeBHcjIt will decrease with the increase of temperature, so you should choose high temperature when you need to work in a high temperature environment.Hcjof the brand.
magnetic energy product(BH)Unit is coke/Meters3（J/m3) or high•Ao (GOe） 1 MGOe≈7. 96k J/m3
any point on the demagnetization curveBandHThe product of bothBHWe call it the energy product,AndB×HThe maximum value of is called the maximum magnetic energy product.(BH)max. The magnetic energy product is one of the important parameters of the energy stored in the constant magnet,(BH)maxThe larger the magnet, the greater the magnetic energy. When designing the magnetic circuit, the working point of the magnet should be as close as possible to the maximum magnetic energy product.BandHNearby.
isotropic magnet:A magnet with the same magnetic properties in any direction.
anisotropic magnets:The magnetic properties will be different in different directions; and there is a direction in which the magnet with the highest magnetic performance is obtained when oriented. Sintered NdFeB permanent magnets are anisotropic magnets.

Orientation direction:The direction in which an anisotropic magnet can obtain the best magnetic properties is called the orientation direction of the magnet. Also known “orientation axis”,“easy magnetization axis”.

Magnetic field strength:Refers to the size of a magnetic field somewhere in space,Hindicates that its unit is/Meters (A/m）。
Magnetization:Refers to the sum of the magnetic moment vectors per unit volume inside the material, usingMThe unit is Ann./Meters (A/m）。
Magnetic induction intensity:magnetic induction intensityBThe definition of is:B= m0(H M), in whichHandMare magnetization and magnetic field strength, respectively, whileμ0is the vacuum permeability. Magnetic induction intensity is also called magnetic flux density, that is, the magnetic flux per unit area. The unit is Tesla (T）。 
Flux:The total magnetic induction in a given area. When the magnetic induction intensityBevenly distributed on the surface of the magnetAWhen, the magnetic fluxΦThe general formulaΦ = b×a. magnetic fluxSIThe unit is Maxwell.
Relative permeability:The ratio of the permeability of the medium to the permeability of the vacuum, I .e.μr= Μ/mo. InCGSIn the system of units,μo=1. In addition, the relative magnetic permeability of air is often taken as the value in actual use.1In addition, the relative permeability of copper, aluminum and stainless steel materials is also approximately.1.

Magnetic Conductive:magnetic fluxΦwith the magnetomotive forceFratio, similar to the conductance in a circuit. It is a physical quantity that reflects the magnetic permeability of materials.
permeability coefficientPc :Also for the demagnetization coefficient, on the demagnetization curve, the magnetic induction intensityBdand magnetic field strengthHdof the ratio, I .e.Pc =Bd/HdThe permeability coefficient can be used to estimate the flux value under various conditions. For isolated magnetsPconly related to the size of the magnet, the demagnetization curve andPcThe intersection of the lines is the working point of the magnet,PcThe larger the magnet, the higher the operating point, the less likely it is to be demagnetized. In general, for an isolated magnet orientation length is relatively largePcThe bigger. ThereforePcIt is an important physical quantity in the design of permanent magnetic circuit.