01Magnetische Kenndaten - gesinterte Seltenerdmagnete

 

Energy product

(B*H)max.

Remanence

Br

rev. Temp.- coeff.

von Br

Coercivity

HcB      HcJ

Ferric induction

Max. operating temp. Density
Rare earth magnets 1) kJ/m3
(typ.)
kJ/m3
(min.)
mT
(typ.)
mT
(min.)
ca. %/K kA/m
(min.)
kA/m
(min.)
kA/m
(min.)
ca. °C ca. g/cm3
SmCo5 143/143 q anisotropic 151 143 920 900 -0,045 2) 680 1433 3500 250 3) 8,3
SmCo5 160/143 q anisotropic 167 160 940 920 -0,045 2) 710 1433 3500 250 3) 8,3
Sm2Co17 207/143 q anisotropic 223 207 1080 1030 -0,030 2) 700 1600 3500 300 3) 8,3
Sm2Co17 180/160 w anisotropic 200 180 1040 980 -0,032 2) 700 1600 4300 350 3) 8,3
NdFeB 180/250 w anisotropic 210 180 1050 1000 -0,080 2) 720 2500 2000 220 3) 7,6
NdFeB 200/220 w anisotropic 230 200 1110 1050 -0,080 2) 790 2200 2000 190 3) 7,6
NdFeB 230/175 w anisotropic 260 230 1190 1130 -0,090 2) 840 1750 2400 160 3) 7,6
NdFeB 250/125 w anisotropic 280 250 1230 1170 -0,100 2) 840 1250 2400 130 3) 7,5
NdFeB 210/250 h anisotropic 240 210 1110 1050 -0,080 2) 800 2500 2000 220 3) 7,6
NdFeB 230/220 h anisotropic 255 230 1160 1100 -0,080 2) 840 2200 2000 190 3) 7,6
NdFeB 250/175 h anisotropic 295 250 1240 1180 -0,090 2) 860 1750 2400 160 3) 7,6
NdFeB 270/125 h anisotropic 300 270 1280 1220 -0,100 2) 870 1250 2400 130 3) 7,5
NdFeB 300/125 h anisotropic 330 300 1320 1260 -0,100 2) 900 1250 2400 130 3) 7,5
NdFeB 263/111 q anisotropic 275 263 1210 1170 -0,110 2) 868 1114 2400 100 3) 7,6
NdFeB 358/111 q anisotropic 375 358 1390 1360 -0,110 2) 907 1114 2400 100 3) 7,6
NdFeB 223/135 q anisotropic 235 223 1110 1080 -0,110 2) 796 1353 2400 120 3) 7,6
NdFeB 287/135 q anisotropic 300 287 1240 1220 -0,110 2) 899 1353 2400 120 3) 7,6
NdFeB 342/135 h anisotropic 355 342 1350 1320 -0,110 2) 907 1353 2400 120 3) 7,6
NdFeB 247/159 q anisotropic 260 247 1160 1130 -0,110 2) 820 1592 2400 150 3) 7,6
NdFeB 287/159 q anisotropic 300 287 1240 1220 -0,110 2) 907 1592 2400 150 3) 7,6
NdFeB 318/159 q anisotropic 330 318 1310 1280 -0,110 2) 907 1592 2400 150 3) 7,6
NdFeB 223/199 q anisotropic 235 223 1100 1080 -0,110 2) 804 1990 2400 180 3) 7,6
NdFeB 263/199 q anisotropic 275 263 1200 1170 -0,110 2) 860 1990 2400 180 3) 7,6
NdFeB 223/238 q anisotropic 235 223 1110 1080 -0,110 2) 796 2387 2400 200 3) 7,6
NdFeB 263/238 q anisotropic 275 263 1200 1170 -0,110 2) 836 2387 2400 200 3) 7,6
NdFeB 247/262 q anisotropic 260 247 1160 1130 -0,110 2) 820 2624 2400 230 3) 7,6

 

 

1)All values were determined with standard samples according to IEC 60404-5. With unusual geometries, especially with thin walls or narrow pole pitches, deviations from the material data can occur.

2)In the temperature range from 20 °C to 100 °C.

3)The max. operating temperature depends on the magnet dimension and the specific application. Please contact our application engineering for more information.

4)For binder PA 6 the magnetic values for HcB min./HcB typ. are reduced by -10 kA/m each and HcJ min./HcJ typ. by -30 kA/m each.

5) For magnets with PPS as binder, the chemical resistance to oils, grease, motor oils etc. is significantly better than for PA-bonded magnets; however this has to be checked in individual cases.

6)On request.

w: axially pressed in the diet

h: highly residual materials - isostatically pressed and separated or diametrically pressed in the die

pw: plastic bonded, pressed

p: plastic bonded, injection-moulded

q: diametrical, pressed in tool

02Term definiton

Barium "Ba":

Chemical element of the second group (alkaline earths). The most important mineral is the heavy spar. During magnet production it is added to the iron oxide in the form of barium carbonate, and results when presintering in the compound BaO • 6Fe2O3 (barium ferrite).

 

Strontium "Sr":

Chemical element of the second group (alkaline earths). It is found in the minerals strontianite and coelestine. Strontium is added in form of strontium carbonate instead of barium carbonate and results in hardferrite magnets with specially high coercive field strength.

 

Isotropic:

Description that a property is independent of the direction. For a magnet, this means that all molecular magnets (the smallest magnetic particles) have different distributions. This apparent chaos balances the positions of all the molecular magnets, thus also balancing their effect toward the exterior. If a magnet prepared under isotropic conditions is magnetized, only the molecular magnets already oriented in the direction of magnetization will be magnetized. This is why magnets of the same material prepared under isotropic conditions are weaker than magnets prepared under anisotropic conditions.

 

The opposite of isotropic describes that a property depends on the direction. For a magnet, this means that all molecular magnets have the same orientation. This can be achieved by preferential orientation of the base material. The magnetic values of the magnets prepared under anisotropic conditions are clearly higher than those of the magnets prepared under isotropic conditions.

Dry-pressed:

Description of production procedure of dry molded magnets. Dry molded magnets are manufactured from magnetic powder. This technique is mostly used for small magnets.

 

Description of production procedure of wet molded magnets. Wet molded magnets are manufactured from wet magnetic mud. The magnetic values of the wet molded magnets are better than those of dry molded magnets. However, there are only few possibilities of forming the wet molded magnets and the molding cycles are much longer.

 

The final values Br (remanence), Hc (coercive field strength) and (B*H)max. (energy product) are the most important magnetic properties of a permanent magnet. The greatest possible energy product (B*H)max. describes the highest energy density that can be achieved with a material. In general, the following applies: The higher the energy density, the smaller the magnetic volume (V) required for a certain task under otherwise identical conditions.

Remanence is understood as meaning the remaining magnetism in a particle, after removing the magnetizing field. The term remanence is the associated remaining flux density. The remaining magnetism is formed by a previously used magnetic field, such as that of an electrified coil giving the particle its own magnetic field by virtue of induction.

Stands for the reversible temperature coefficient and represents the relative change in a physical property as a function of a change in temperature by one Kelvin.

Stands for the magnetic field strength required to completely demagnetize ferromagnets. A high coercive field strength means that a magnet exhibits high stability against demagnetization. Please note that the coercive field strength is highly temperature-dependent.

Denotes the maximum temperature at which the magnet can still be used. It is far below the Curie temperature. Please note that the maximum operating temperature is a function of the magnet geometry and the opposite fields occurring in use. This means that the values stated in the data sheets are only guide values.

The density of a body is the relationship between the mass and the volume and describes whether a body is relatively light or heavy.

[1]: Harry H. Binder: Lexikon der chemischen Elemente, S. Hirzel Verlag, Stuttgart 1999.