GM440A
Magnetic properties toroidal boxed magnetic cores from amorphous and nanocrystalline alloys
GAMMAMET® 440A
Magnetic cores GAMMAMET® 440A are made of a ribbon by thickness 25 microns with nanocrystalline structure. The ribbon is produce by means of fast incandescence from an alloy on the basis of iron. After thermal processing in a longitudinal magnetic field magnetic cores have high rectangular loop of a magnetic hysteresis.
Magnetic cores may be produced with any standard sizes with external diameter up to 600 mm, with internal diameter not less than 8 mm, proportional 5 mm at height and are delivered in protective containers.
Sizes list of magnetic cores in protective containers you can see in Table 1. Weight and geometrical sizes of toroidal boxed magnetic cores
All magnetic cores have a class of thermal stability A (105°C). At will of the customer also magnetic cores may be produced with class F (155°C).
Full service life of magnetic cores - 30 years.
Magnetic cores GAMMAMET® 440А replace soft magnetic alloys Fe- and Ni- alloys and ferrite with a rectangular loop of a magnetic hysteresis. Next table of magnetic parameters is agreed with specifications ТУ 1261-030-12287107-2007:
| Magnetic core | Squareness ratio Kp800, not less | Coercive force, А/м, no more | B800, T, not less |
|---|---|---|---|
| GM 440А | 0,8 | 8,0 | 1,45 |
Use area: power transformers, magnetic amplifiers, pulse transformers, magnetic keys
GAMMAMET® owns following patents of Russia which are used at manufacture of magnetic cores GM440А: 2149473.
The detailed information about magnetic properties of GM440А can be found in the book: Starodubtsev J.N., Belozerov V.J. "Magnetic properties amorphous and nanocrystalline alloys"
| Magnetic induction, В800 | 1,5 T |
|---|---|
| Maximum permeability | 200000 |
| Coercive force | 4 A/m |
| Squareness ratio Br/B800 | 0,9 |
| Saturation magnetostriction | 25×10-6 |
| Specific electroresistance | 1,3×10-6 Om×m |
| Density | 7300 kg/m3 |
| Curie temperature | 420°C |
| Specific magnetic losses at frequencyf<3 kHz | |
| P = 2×10-4f1,4Bm1,65 (W/kg) | |
| Specific magnetic losses at frequency3<f<200 kHz | |
| P = 2,8×10-4f1,5Bm1,85 (W/kg), Bm≤0,1 T | |
| P = 10-4f1,5Bm1,4 (W/kg), Bm≤0,1 T | |
| f – frequency (Hz), Bm – maximal magnetic induction (T) | |
Loop of a magnetic hysteresis
Curves of magnetization
Magnetic permeability
