Permalloy
The permalloy.
Permalloy is a precision alloy of iron (18-55 %) and Nickel (45 – 82%), characterized by magnetic properties. Can be additionally alloyed with several other components.
Alloys
Description:
Permalloy is a precision alloy of iron (Fe) (18-55 %) and Nickel (Ni) (45-82 %), which is characterized by soft magnetic properties. Permalloy can be further alloyed with several other components, for example, molybdenum (Mo), copper (Cu), chromium (Cr), silicon (Si).
Magnetic means magnetized easily.
The permalloys are divided into two groups: misconceive – up to 50% of Nickel and Nickel – up to 83%. Heat treatment Nickel permalloys harder than misconceived. Saturation induction Nickel permalloys and a half times lower than neskonchaemyj permalloys. Magnetic permeability of Nickel permalloys are several times higher than misconceived. Resistivity Nickel permalloys are almost three times less than misconceived.
Permalloy is used for the manufacture of transformer plates, elements of magnetic recording heads, protective covers circuits and coils, sensitive to the magnetic field, the magnetic field sensors in the chips, rentals for shielding from magnetic fields: facilities for MRI, electron microscopes and other sensitive instruments. In the past, the permalloy was used to reduce signal distortion in the telecommunications cables as the compensator their distributed capacitance.
Properties:
– mechanical soft and corrosion resistant material,
– has a face-centered cubic lattice and cubic magnetic anisotropy,
– an electrical resistivity of 2×10-5 Ω·cm for the alloy grade 81Н,
– saturation induction up to 2 TL
– has a high magnetic permeability (the maximum relative magnetic permeability μ ~ 100 000),
– magnetoresistive ratio is in the range from 2 to 4 % (2% for fields of the order of 3.75 um or 300 A/m),
– has a coercive force,
– has almost zero magnetostriction, and significant magnetoresistive effect,
– the electrical resistance of the permalloy changes in the limit 5%, depending on the strength and direction of the current magnetic field.
