Alloy 77，Nilomag 77 Forgings，

British Specs:，American Specs: AMS 6519 Bar, Tube, Forging，German Specs:

Alloy 77 (Nilomag 77 Wire) - Introduction with Composition, Properties, Applications and Product Forms

Alloy 77, commercially known as Nilomag 77, is a nickel-iron-magnesium alloy celebrated for its unique combination of high magnetic permeability, good corrosion resistance, and excellent formability. This specialized material is available in a wide range of forms to meet diverse industrial needs, including Bar (Round bar, Flat bar), Ribbon, Wire, Rods, Tube, Pipe, Foil, Plate, Sheet, Strip, and Forging Stock. Nilomag 77 Wire, in particular, is highly valued for its magnetic properties and flexibility, making it ideal for precision magnetic components, electrical sensors, and intricate wiring in corrosive environments. Below is a detailed overview of its chemical composition, key properties, practical applications, and available product forms.

Chemical Composition

The precisely engineered chemical composition of Alloy 77 (Nilomag 77) is the foundation of its unique magnetic properties and corrosion resistance. The typical composition (by weight) is as follows:

Nickel (Ni): 75-78% (primary matrix element, providing magnetic permeability and corrosion resistance)

Iron (Fe): 20-22% (enhances magnetic properties and mechanical strength)

Magnesium (Mg): 1.5-2.5% (critical for optimizing magnetic permeability and improving formability)

Copper (Cu): ≤ 0.5% (aids in corrosion resistance and mechanical stability)

Manganese (Mn): ≤ 0.3% (assists in deoxidation during manufacturing and improves weldability)

Silicon (Si): ≤ 0.2% (minimized to prevent the formation of brittle phases, preserving ductility)

Carbon (C): ≤ 0.03% (controlled to avoid carbide precipitation, which could impair magnetic properties)

Sulfur (S): ≤ 0.01% (kept at very low levels to ensure good ductility and prevent hot shortness)

Other trace elements: ≤ 0.5% total (including chromium and cobalt, minimized to maintain magnetic performance)

This balanced composition synergistically delivers the alloy's signature combination of high magnetic permeability, corrosion resistance, and formability, making it suitable for specialized magnetic and electrical applications.

Key Properties

Alloy 77 (Nilomag 77 Wire) and its various forms exhibit a unique set of properties that make them indispensable in magnetic, electrical, and corrosive environments:

Mechanical Properties (room temperature, annealed condition):

Tensile strength: 400-520 MPa (58,000-75,400 psi)

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

Elongation (in 50 mm): 35-50% (excellent ductility, enabling complex forming, bending, and drawing into wire and thin forms)

Hardness: 90-130 HB (Brinell hardness, indicating good machinability and workability)

Magnetic Properties:

Magnetic permeability: High initial permeability (≥ 8000 at 0.001 T) and maximum permeability (≥ 50,000 at 0.1 T), making it ideal for magnetic cores and sensors

Coercivity: Low coercivity (≤ 0.5 A/m), ensuring efficient magnetization and demagnetization

Saturation induction: 1.5-1.6 T, providing strong magnetic response in applications requiring high flux density

Curie temperature: 500-520°C (932-968°F), maintaining magnetic properties at elevated temperatures

Corrosion Resistance:

General corrosion resistance: Good resistance to atmospheric corrosion, freshwater, and mild industrial environments

Chemical resistance: Resistant to dilute acids, alkaline solutions, and organic chemicals; less suitable for strong oxidizing acids

Wet corrosion: Resistant to oils, solvents, and mild detergents, ensuring durability in industrial settings

Stress corrosion cracking (SCC): Resistant to SCC in most environments, including moderate chloride-containing solutions

Physical Properties:

Density: 8.2 g/cm³ (0.296 lb/in³)

Thermal conductivity: 18 W/(m·K) at 20°C (68°F)

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

Coefficient of thermal expansion: 13.5 μm/(m·K) (20-100°C)

Modulus of elasticity: 200 GPa (29,000 ksi) at room temperature

Product Forms

Alloy 77 (Nilomag 77) is manufactured in a diverse range of forms to accommodate specialized industrial processes across magnetic, electrical, and aerospace sectors:

Bar: Available as Round bar (diameters from 6 mm to 200 mm) and Flat bar (thickness 5 mm to 100 mm, width 15 mm to 500 mm), ideal for machining into magnetic cores, sensor housings, and precision mechanical components.

Ribbon: Thin, flat strips (thickness 0.05 mm to 1 mm, width 5 mm to 100 mm) used in transformers, inductors, and magnetic shielding components.

Wire: Nilomag 77 Wire (diameters 0.05 mm to 8 mm) offers excellent flexibility and magnetic properties, making it suitable for solenoid coils, magnetic sensors, and precision wiring in electrical systems.

Rods: Solid cylindrical rods (diameters 3 mm to 50 mm) suitable for magnetic cores, electrical terminals, and structural supports in magnetic equipment.

Tube and Pipe: Seamless options (outer diameter 5 mm to 150 mm, wall thickness 0.5 mm to 8 mm) for magnetic shielding and fluid transport in specialized systems.

Foil: Ultra-thin sheets (thickness 0.005 mm to 0.1 mm) used in lightweight magnetic shielding, transformers, and precision electrical components.

Plate and Sheet: Flat forms (plate: thickness 4 mm to 80 mm; sheet: 0.2 mm to 4 mm) for fabricating magnetic cores, shielding panels, and electrical enclosures.

Strip: Narrow, flat strips (thickness 0.05 mm to 2 mm, width 10 mm to 200 mm) for precision manufacturing in magnetic sensors, relays, and electrical contacts.

Forging Stock: Billets and ingots for hot forging into complex shapes such as magnetic yokes, valve components, and aerospace magnetic hardware.

Applications

The exceptional properties of Alloy 77 (Nilomag 77 Wire) across its various forms make it a critical material in industries requiring high magnetic permeability, corrosion resistance, and formability:

Electrical and Electronics:

Magnetic cores: Ribbon and sheet for transformers, inductors, and chokes, leveraging high permeability and low coercivity.

Sensors and actuators: Wire and strip for magnetic sensors, solenoids, and relays, providing precise magnetic response.

Magnetic shielding: Foil and sheet for shielding sensitive electronics from electromagnetic interference (EMI).

Electrical windings: Wire for coils in motors, generators, and magnetic resonance imaging (MRI) equipment.

Aerospace and Defense:

Avionics: Magnetic components (from bar and rod) for navigation systems, gyroscopes, and communication equipment.

Radar systems: Shielding panels (from plate and sheet) and coils (from wire) for radar and sonar systems.

Missile guidance: Precision magnetic sensors (from strip and ribbon) for guidance and control systems.

Industrial and Medical:

Magnetic separators: Plates and bars for separating magnetic materials in mining and recycling processes.

Medical devices: Wire and foil for MRI machines, pacemakers, and other medical equipment requiring magnetic components.

Industrial magnets: Forging stock and bars for manufacturing high-performance magnets and magnetic assemblies.

Specialized Applications by Form:

Wire: Solenoid coils, sensor windings, and precision magnetic wiring in corrosive environments.

Ribbon and Foil: Transformer cores, magnetic shielding, and thin-film magnetic components.

Plate and Sheet: Magnetic cores, shielding panels, and structural components in magnetic systems.

Bar and Rod: Machined magnetic yokes, sensor housings, and precision mechanical components with magnetic properties.

In summary, Alloy 77 (Nilomag 77 Wire) — available in forms from Bar and Wire to Plate and Forging Stock — delivers exceptional magnetic permeability, good corrosion resistance, and excellent formability. Its diverse product forms enable tailored solutions across electrical, aerospace, industrial, and medical sectors, establishing it as a critical material in specialized magnetic applications.

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 2790 gallon liquid totes Special package is available on request.