Key Features:

  1. Permalloy is a Ni-Fe-Mo alloy with small hysteresis loss
  2. Moderate resistance to moisture and general corrosion
  3. High magnetic permeability
  4. Suitable for use as a shielding material
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About Permalloy

Permalloy (Nickel 80%) or Mumetal is a magnetic shielding material that is made from a nickel-iron alloy. It has high permeability and is an ideal material for shielding in constant or low frequency magnetic regions. Nominal hysteresis loss.

Permalloy Applications

Uses of Permalloy include- transformer cores, telephones, securing sensitive medical apparatus in MRI, home theatre systems, shielding electrical systems from magnetic field drifts, tape wound toroids and lamentations where small size and weight factors are crucial.

Common Industrial Nomenclatures: Carpenter HyMu 80, Alloy HyMu 80, Permalloy 80, MIL N 14411C, Comp 1, alloy 4750,  High Perm 49,  Permenorm 5000 H2,  Radiometal 4550, Superimphy T,  Ultraperm 80, Ultravac 80 ®, Vac 80,Carpenter HyMu 80,UNS N14080

Permalloy Specifications: ASTM A-753-78, , MIL-N-14411 B (MR)

Permalloy Shielding Potential

Permalloy has extremely high permeability and nominal coercive force that make it a suitable material for shielding operations. To achieve the desired shielding properties, HyMu 80 is annealed up to 1900oF or 1040oC subsequent to forming processes. Annealing at the elevated temperatures enhances the permeability and shielding properties.

Permalloy Fabrication

Process Annealing: To remove strains and recover an alloy in a soft condition for processing, annealing at 1450oF to 1850oF or 788oC to 1010oC for less than 60 minutes is done. This type of annealing is performed in ammonia, hydrogen or vacuum conditions as the high permeability metals quickly absorb sulfur, oxygen, carbon and other elements that lie in the combustion gases.

Another commonly used annealing method for HyMu 80 alloy is hydrogen annealing. It is annealed from 2050oF to 2150oF or 1121oC to 1177oC for two to four hours. Furnace quenching up to 1100oF and from 1100oF to 700oF, quenching rate 350oF to 600oF per hour is followed. Hydrogen annealing enhances softness and provides suitable magnetic and electrical features.

Carpenter HyMU 80 alloy can be welded using the similar methods to ferrous alloys.

Forms Produced

Permalloy wire Permalloy wire mesh
Permalloy Foil Permalloy sheet


Heanjia Super Metals, America offers all above forms of Permalloy in all standard as well as custom specifications.