Alloys for magnetic shielding

Due to their high permeability 80 % NiFe alloys (MUMETALL®) are the first choice whenever high shielding factors are needed. In case of higher field strengths 50 % NiFe alloys (PERMENORM®) offer a higher saturation flux density and/or are a cost effective option. To shield very high magnetic fields
50 % CoFe alloys (VACOFLUX® 50) are available.

For simpler shielding problems pure iron or some magnetic steels can be used but should be magnetically annealed.

CRYOPERM® is a special composition which enables after suitable magnetic annealing similar magnetic properties than MUMETALL® at room temperature.

Typical magnetic properties after annealing
AlloyCompositionµ4 (50 Hz)HC [A/m]BS [T]TCurie [°C]Thermal expansion [10-6/K] (20...100°C)Specific electrical resistance [µOm]Density [g/cm³]
VITROVAC® 6025 I50X80 % Co2000010,57200121,357,7
VACOPERM® 10080 % NiFe9000020,7840013,50,68,7
MUMETALL®80 % NiFe5000030,8040013,50,68,7
PERMENORM® 5000 H250 % NiFe12000101,55440100,458,25
VACOFLUX® 50 (strip)50 % CoFe1000902,359509,50,358,12
VACOFLUX® 50 (massive)50 % CoFe1000 (static)2002,359509,50,358,12
Soft iron99,9 % Fe1000 (static)802,15770 0,1077,86
CRYOPERM® 1080 % NiFe**** 0,358,7
TRAFOPERM® N33 % SiFe1000 (static)252,03750120,47,65
µ4: µr at 0,4 A/m