Mu-Metal,Hy-Mu 80 Fittings,

Mu-Metal, Hy-Mu 80 Wire - Introduction with Composition, Properties, Applications and Product Forms

Mu-Metal and Hy-Mu 80 are specialized nickel-iron soft magnetic alloys celebrated for their exceptional magnetic shielding capabilities, ultra-high magnetic permeability, and extremely low coercivity. These alloys are engineered to redirect magnetic fields, making them indispensable in applications requiring protection against external magnetic interference. Available in a comprehensive range of forms to meet diverse industrial needs, these materials include Bar (Round bar, Flat bar), Ribbon, Wire, Rods, Tube, Pipe, Foil, Plate, Sheet, Strip, and Forging Stock. Hy-Mu 80 Wire, a high-performance variant, is particularly valued for its precision, flexibility, and consistent magnetic properties, making it ideal for intricate shielding components, sensor coils, and miniature magnetic devices in electronics, aerospace, and medical industries. Below is a detailed overview of their chemical composition, key properties, practical applications, and available product forms.

Chemical Composition

The chemical composition of Mu-Metal and Hy-Mu 80 is carefully optimized to maximize magnetic permeability and minimize coercivity, with Hy-Mu 80 representing a high-nickel grade for enhanced performance. The typical composition (by weight) is as follows:

Mu-Metal (Standard Grade):

Nickel (Ni): 75-80% (the primary alloying element, responsible for ultra-high magnetic permeability and low coercivity)

Iron (Fe): 15-20% (balances the alloy, providing structural stability while supporting magnetic properties)

Copper (Cu): 4-6% (improves ductility, corrosion resistance, and refines grain structure)

Molybdenum (Mo): 2-3% (enhances permeability and increases electrical resistivity, reducing eddy current losses)

Manganese (Mn): 0.5-1.0% (aids in deoxidation during manufacturing, improving magnetic uniformity)

Carbon (C): ≤ 0.03% (kept extremely low to avoid carbide formation, which degrades magnetic properties)

Silicon (Si): ≤ 0.1% (controlled to prevent oxide inclusions that disrupt magnetic domains)

Sulfur (S): ≤ 0.01% (strictly limited to preserve magnetic softness and prevent embrittlement)

Hy-Mu 80:

Nickel (Ni): 80% (higher nickel content than standard Mu-Metal, delivering even higher initial permeability)

Iron (Fe): 15-18%

Molybdenum (Mo): 2-3% (enhances high-frequency performance and permeability)

Copper (Cu): 0-1% (reduced compared to standard Mu-Metal, optimizing for permeability)

Manganese (Mn): 0.5-1.0%

Carbon (C): ≤ 0.02%

Other impurities: ≤ 0.5%

This precise composition, combined with a specialized annealing process in a hydrogen atmosphere (to eliminate carbon and oxygen, which degrade magnetic properties), ensures the alloys’ exceptional shielding performance.

Key Properties

Mu-Metal and Hy-Mu 80 (including Hy-Mu 80 Wire) exhibit extraordinary magnetic properties that set them apart as premier shielding materials:

Magnetic permeability (initial/ maximum):

Mu-Metal: Initial permeability (μ₀) up to 50,000; maximum permeability (μₘ) up to 300,000

Hy-Mu 80: Initial permeability (μ₀) up to 80,000; maximum permeability (μₘ) up to 400,000 (superior to standard Mu-Metal, ideal for high-sensitivity applications)

Coercivity (Hc): ≤ 0.8 A/m (extremely low, indicating exceptional magnetic softness and easy magnetization/demagnetization)

Saturation induction (Bs): 0.6-0.8 T (moderate saturation, suitable for low magnetic field environments where shielding is critical)

Curie temperature: 350-400°C (the temperature above which magnetic properties diminish, ensuring stability in ambient conditions)

Electrical resistivity: 40-60 μΩ·cm (higher than pure iron, reducing eddy current losses in AC applications)

Mechanical Properties (annealed condition):

Tensile strength: 350-450 MPa (50,800-65,300 psi)

Yield strength (0.2% offset): 120-200 MPa (17,400-29,000 psi)

Elongation (in 50 mm): 25-40% (excellent ductility, enabling forming into thin foils, wires, and complex shapes)

Hardness: 110-160 HB (Brinell hardness, reflecting good workability and machinability)

Physical Properties:

Density: 8.7-8.9 g/cm³ (0.314-0.322 lb/in³)

Thermal conductivity: 10-14 W/(m·K) at 20°C (68°F)

Coefficient of thermal expansion: 13-16 μm/(m·K) (20-100°C)

Melting point: 1420-1460°C (2588-2660°F)

Product Forms

Mu-Metal and Hy-Mu 80 are manufactured in a diverse range of forms to accommodate specialized magnetic shielding and precision magnetic applications:

Bar: Available as Round bar (diameters from 5 mm to 100 mm) and Flat bar (thickness 3 mm to 50 mm, width 10 mm to 200 mm), used for machining shielding enclosures, magnetic cores, and structural components in high-precision devices.

Ribbon: Thin, flat strips (thickness 0.01 mm to 0.5 mm, width 1 mm to 100 mm) ideal for high-frequency shielding, transformer cores, and sensor components, where minimal eddy current losses are critical.

Wire: Hy-Mu 80 Wire (diameters 0.02 mm to 5 mm) offers exceptional flexibility and uniform magnetic properties, suitable for shielding mesh, precision coils, and miniature magnetic sensors.

Rods: Solid cylindrical rods (diameters 2 mm to 30 mm) used in small shielding components, magnetic guides, and calibration tools.

Tube and Pipe: Hollow forms (outer diameter 3 mm to 200 mm, wall thickness 0.1 mm to 10 mm) for shielding cables, optical fibers, and sensor probes from external magnetic fields.

Foil: Ultra-thin sheets (thickness 0.001 mm to 0.1 mm) — the most common form for shielding — used in flexible enclosures, wrapping sensitive electronics, and MRI equipment.

Plate and Sheet: Flat forms (plate: thickness 1 mm to 20 mm; sheet: 0.05 mm to 1 mm) for fabricating large shielding enclosures, laboratory shields, and magnetic barriers.

Strip: Narrow, flat strips (thickness 0.05 mm to 1 mm, width 2 mm to 100 mm) for precision shielding components, such as relay shields and inductor covers.

Forging Stock: Billets and ingots for hot forging into custom shielding structures, such as large enclosures for power transformers or scientific instruments.

Applications

The exceptional magnetic shielding properties of Mu-Metal and Hy-Mu 80 (including Hy-Mu 80 Wire) across their various forms make them critical materials in industries requiring protection against magnetic interference:

Electronics and Telecommunications:

Magnetic shielding: Enclosures, foil wraps, and tubes (from foil, sheet, and tube) to protect sensitive electronics such as oscillators, amplifiers, and radar components from external magnetic fields.

Precision sensors: Coils and shielding (from wire and ribbon) in magnetometers, fluxgate sensors, and compasses, ensuring accurate measurements in noisy magnetic environments.

Data storage: Shielding for hard disk drives, magnetic tape systems, and quantum computing components (from sheet and foil), preventing data corruption from stray magnetic fields.

Aerospace and Defense:

Avionics: Shielding for navigation systems, GPS receivers, and communication equipment (from sheet, tube, and foil) to maintain signal integrity in high-interference environments (e.g., near radar or power lines).

Military sensors: Magnetic shields for submarine detection systems, mine detectors, and missile guidance components (from plate and forging stock), ensuring sensitivity to weak magnetic signals.

Satellite systems: Lightweight shielding for onboard electronics (from foil and wire mesh) to protect against cosmic and terrestrial magnetic interference.

Medical Devices:

MRI equipment: Shielding enclosures and liners (from plate, sheet, and foil) to contain the strong magnetic fields of MRI scanners and protect nearby equipment and personnel.

Medical sensors: Shielding for EKG, EEG, and magnetoencephalography (MEG) devices (from wire and ribbon), ensuring accurate detection of weak biological magnetic signals.

Implantable devices: Miniature shielding components (from wire and foil) for pacemakers and neurostimulators, preventing interference from external magnetic fields.

Scientific Research:

Laboratory equipment: Shielding for cryostats, particle detectors, and nuclear magnetic resonance (NMR) devices (from plate, tube, and forging stock), isolating experiments from ambient magnetic noise.

Material science: Magnetic cores and shields (from ribbon and wire) for studying magnetic materials, enabling precise control of magnetic environments.

Astronomy: Shielding for telescopes and space-based instruments (from foil and sheet) to protect against solar and galactic magnetic fields.

Specialized Applications by Form:

Wire: Shielding mesh for windows, precision coils in sensors, and miniature shielding components in wearables.

Foil: Flexible wrapping for cables, small electronic components, and temporary shielding in research setups.

Tube/Pipe: Shielding for optical fibers, sensor probes, and medical catheters requiring protection in magnetic environments.

Plate/Sheet: Large enclosures for data centers, power transformers, and laboratory rooms needing comprehensive magnetic isolation.

In summary, Mu-Metal and Hy-Mu 80 (including Hy-Mu 80 Wire) — available in forms from Bar and Wire to Plate and Forging Stock — deliver exceptional magnetic shielding performance, ultra-high permeability, and versatility. Their diverse product forms enable tailored solutions across electronics, aerospace, medical, and scientific sectors, establishing them as critical materials in applications requiring precise protection against magnetic interference.

Packing of Standard Packing: 

Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and steel drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 1604 gallon liquid totes Special package is available on request.