In this post, we would like to introduce you some terms about the magnet. And that will not too difficult to understand. Most of the terms, will always be used in our daily business. so pls pay attention at this post.
When the Curie temperature is reached, the magnetic material loses magnetism.
The working temperature is the highest temperature that a magnet can be exposed to without permanent magnetic loss. It is an approximate value since there is a dependency on sizing. Factors such as mechanical or chemical stress can further limit the maximum service temperature. It is very important to check the temperature because the high temperature will “kill” the magnet. It will be dead.
Energy product (B × H) max
The maximum energy product from the flux density B and the field strength H is the most important quality value of a magnetic material. The higher the energy product, the greater the magnetic energy. The larger the (B × H) max value of a magnetic material, the smaller the magnet volume required for a particular task can be, given otherwise identical conditions.
Coercive force H c
Coercive field strength is the field strength that must be used to eliminate magnetization. The higher the value, the higher the magnetization resistance. One distinguishes HcB and HcJ.
Remanence (B r )
Remanence refers to the remaining magnetization in a magnet material that has been magnetized to saturation in a closed loop. The remanence is given in Gauss (G), Tesla (T) or Millitesla (mT).
|Magnetic material||energy product||Retention||coercivity||Temperature coefficient||Max. Operating temperature||Curie temperature||density|
|(B × H) max kJ / m 3||B r mT||H cB kA / m||H cJ kA / m||per 1 ° C||° C||° C||g / cm 3|
|Barium ferrite isotropic||7.2 – 7.6||210 – 220||130 – 135||220||-0.2%||250||450||4.9|
|Barium ferrite anisotropic||28.9 – 29.5||390 – 400||145 – 160||150 – 165||-0.2%||250||450||4.9|
|Strontium ferrite anisotropic||24.5 – 25.5||350 – 370||210-245||220 – 255||-0.2%||250||450||4.9|
|AINiCo 500||35 – 36||1120 – 1160||47 – 49||47 – 49||-0.02%||400||890||7.3|
|Samarium Cobalt SmCo5||140 – 150||850-890||620-670||1100 – 120||-0.04%||250||720||8.3|
|Samarium Cobalt Sm2Co17||190 – 205||1000 – 1050||680 – 750||1195 – 1500||-0.03%||250||800||8.3|
|Neodymium Iron Boron NdFeB N35 *||260 – 285||1180-1220||860-915||> 955||-0.13%||80||310||7.4|
|Neodymium Iron Boron NdFeB N48 *||358 – 392||1370 – 1410||859 – 950||> 955||-0.13%||80||310||7.4|
Values determined at 20 ° C temperature. * Versions up to 220 ° C operating temperature available.