FERITTE MAGNETS

The isotropic oxide permanent magnet are made by the powder metallurgy technology from very fine powder of the composition (Ba, Sr, Pb)O.6Fe2O3. The pressing carry out without external magnetic field, as a result the magnetic properties of obtaining magnets are isotropic. This allows to make multipole magnets.

The mechanical and electrical properties are like ceramic materials. Grinding or cutting with a diamond wheel only can process them. Their electrical resistance is about 108.cm.

The oxide permanent magnets have high coercivity and fairly low remanent magnetization. They require very high magnetizing field - about 800 kA/m. Curie -temperature is 450C, maximum temperature of use is 200C and temperature coefficient of remanence - 0.2%/C.

PRAMIZ Ltd. offers barium and strontium isotropic oxide permanent magnets. They magnetic properties are presented in the table.

Material

Minimum values

(B.H) max

Br

BHc

JHc

kJ/m3

MG.Oe

T

G

kA/m

Oe

kA/m

Oe

Hfer 6/19

6

0.75

0.17

1700

104

1300

190

2400

Hfer 8/22

8

1.0

0.21

2100

136

1700

220

2750

The oxide permanent magnets have many applications:
- Mono- and multi pole segments for rotors and stators of small motors and stepping motors, generators;
- Magnet elements in switch sensors;
- In relays of telecommunication systems;
- Magnetic couplings for transmit mechanical motions through solid walls;
- Cores in microwave devices;
- Holding elements and etc.

To answer the client's requirements we need the following information:
- A drawing with a shape and dimensions of the magnet, a condition of the surfaces. The cross-section of the magnets can be from 10 to 1000 mm2 and the length from 2 to 50 mm. We recommend the length to be up to 4 times the diameter;
- A type material, according the table and other requirements;
- A direction of magnetization or a configuration of poles;
- Conditions of work of the magnets: a configuration with other magnets or cores, air gaps, demagnetization fields and etc.;
- A condition of magnets: magnetized or demagnetized;
- A quantity.

Receiving this information we can answer about a price, a term of delivery and etc.