Alloy 475,Nilo 475 Plate,UNS K95000

Alloy 475,Nilo 475 Wire,UNS K95000

Alloy 475 (Nilo 475 Wire, UNS K95000) - Introduction with Composition, Properties, Applications and Product Forms

Alloy 475, commercially known as Nilo 475 and designated by UNS K95000, is a nickel-iron-cobalt controlled expansion alloy renowned for its precise thermal expansion characteristics and excellent mechanical properties. This alloy is specifically engineered to maintain dimensional stability over a wide temperature range, making it indispensable in applications requiring tight thermal expansion matching with other materials, such as glass, ceramics, and certain metals. It is available in a comprehensive 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. Nilo 475 Wire, in particular, is valued for its consistent expansion properties, flexibility, and precision, making it ideal for intricate components in electronics, aerospace, and optical industries. Below is a detailed overview of its chemical composition, key properties, practical applications, and available product forms.

Chemical Composition

The precisely balanced chemical composition of Alloy 475 (Nilo 475, UNS K95000) is the foundation of its controlled thermal expansion and mechanical stability. The typical composition (by weight) is as follows:

Nickel (Ni): 46-48% (primary element contributing to controlled thermal expansion and corrosion resistance)

Iron (Fe): 38-40% (balances the alloy, providing structural strength and supporting thermal stability)

Cobalt (Co): 14-16% (critical for fine-tuning thermal expansion coefficients to match specific materials like glass)

Carbon (C): ≤ 0.05% (kept low to avoid carbide formation, which can disrupt thermal uniformity)

Manganese (Mn): ≤ 0.5% (aids in deoxidation during manufacturing, improving ductility)

Silicon (Si): ≤ 0.3% (controlled to prevent oxide inclusions and maintain thermal consistency)

Sulfur (S): ≤ 0.01% (strictly limited to ensure good ductility and avoid embrittlement)

Phosphorus (P): ≤ 0.02% (kept low to preserve corrosion resistance and thermal stability)

This carefully engineered composition, with its balanced blend of nickel, iron, and cobalt, delivers the alloy's signature controlled thermal expansion, ensuring dimensional stability across temperature fluctuations and compatibility with other materials in high-precision assemblies.

Key Properties

Alloy 475 (Nilo 475 Wire, UNS K95000) and its various forms exhibit a unique set of properties that make them indispensable in applications requiring precise thermal expansion control:

Coefficient of thermal expansion (CTE):

20-300°C: 4.5-5.5 × 10⁻⁶ /°C (extremely low and controlled, enabling compatibility with borosilicate glass and ceramics)

20-400°C: 5.0-6.0 × 10⁻⁶ /°C (maintains stability at moderately elevated temperatures)

Thermal conductivity: 16-18 W/(m·K) at 20°C (68°F)

Melting point: 1430-1470°C (2594-2678°F)

Curie temperature: 410-430°C (the temperature above which ferromagnetic properties diminish)

Mechanical Properties (annealed condition):

Tensile strength: 450-550 MPa (65,300-79,800 psi)

Yield strength (0.2% offset): 180-250 MPa (26,100-36,300 psi)

Elongation (in 50 mm): 25-35% (excellent ductility, enabling forming into wires, ribbons, and complex shapes)

Hardness: 130-170 HB (Brinell hardness, reflecting good machinability and workability)

Physical and Magnetic Properties:

Density: 8.2-8.4 g/cm³ (0.296-0.303 lb/in³)

Modulus of elasticity: 180-190 GPa (26,100-27,500 ksi) at room temperature

Magnetic permeability: Ferromagnetic at room temperature, with high permeability (useful in certain magnetic applications)

Corrosion resistance: Good resistance to atmospheric corrosion and mild chemicals, ensuring durability in industrial environments

Product Forms

Alloy 475 (Nilo 475, UNS K95000) is manufactured in a diverse range of forms to accommodate specialized applications requiring controlled thermal expansion:

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), ideal for machining into precision hardware, leadframes, and structural components in thermal management systems.

Ribbon: Thin, flat strips (thickness 0.01 mm to 0.5 mm, width 1 mm to 100 mm) used in electronic packaging, thermostats, and precision seals requiring tight thermal expansion matching.

Wire: Nilo 475 Wire (diameters 0.02 mm to 5 mm) offers consistent thermal properties and flexibility, suitable for thermocouple leads, precision coils, and wire bonds in electronics.

Rods: Solid cylindrical rods (diameters 2 mm to 30 mm) used in glass-to-metal seals, sensor supports, and calibration tools.

Tube and Pipe: Hollow forms (outer diameter 3 mm to 100 mm, wall thickness 0.1 mm to 5 mm) for thermal sleeves, protective tubing for sensors, and components in optical systems.

Foil: Ultra-thin sheets (thickness 0.001 mm to 0.1 mm) used in flexible thermal barriers, thin-film electronics, and precision gaskets.

Plate and Sheet: Flat forms (plate: thickness 1 mm to 20 mm; sheet: 0.05 mm to 1 mm) for fabricating flanges, heat sinks, and structural parts in optical and electronic equipment.

Strip: Narrow, flat strips (thickness 0.05 mm to 1 mm, width 2 mm to 100 mm) for precision components such as thermostat bimetals, relay contacts, and seal rings.

Forging Stock: Billets and ingots for hot forging into custom shapes, such as large flanges and structural components in aerospace thermal systems.

Applications

The controlled thermal expansion and mechanical stability of Alloy 475 (Nilo 475 Wire, UNS K95000) across its various forms make it a critical material in industries requiring precision thermal management and material compatibility:

Electronics and Telecommunications:

Glass-to-metal seals: Components (from bar, rod, and wire) for vacuum tubes, connectors, and feedthroughs, where the alloy’s CTE matches borosilicate glass to prevent seal failure during temperature changes.

Electronic packaging: Leadframes, headers, and heat sinks (from sheet, strip, and plate) for semiconductors and integrated circuits, ensuring dimensional stability during soldering and operation.

Thermal sensors: Thermocouple leads, resistance temperature detectors (RTDs), and sensor housings (from wire, tube, and ribbon) requiring accurate temperature measurement without thermal expansion-induced errors.

Aerospace and Aviation:

Optical systems: Structural components for telescopes, laser systems, and avionics displays (from plate, sheet, and bar) where thermal expansion must be minimized to maintain optical alignment.

Thermal management: Heat shields, thermal sleeves, and ducting (from tube, sheet, and strip) for aircraft engines and avionics, ensuring compatibility with adjacent materials.

Instrumentation: Precision coils, connectors, and wiring (from wire and ribbon) for aerospace sensors and navigation systems, resisting thermal stress.

Optical and Medical Devices:

Optical assemblies: Mounts, brackets, and seals (from bar, plate, and strip) for lenses, mirrors, and fiber optic systems, maintaining alignment across temperature ranges.

Medical imaging: Components for MRI, CT scan, and laser equipment (from sheet, tube, and wire) requiring dimensional stability in varying thermal environments.

Laboratory instruments: Seals, valves, and structural parts (from forging stock, bar, and tube) for spectrometers and analytical devices, ensuring measurement accuracy.

Automotive and Industrial:

Automotive electronics: Sensors, connectors, and thermal management components (from strip, wire, and sheet) for engine control units and advanced driver-assistance systems (ADAS).

Thermostats and bimetals: Ribbon and strip forms used in temperature-regulating devices, leveraging controlled expansion to actuate switches.

Vacuum systems: Seals, flanges, and tubing (from tube, bar, and plate) for industrial vacuum chambers, preventing leaks due to thermal cycling.

Specialized Applications by Form:

Wire: Thermocouple leads, precision coils, and wire bonds in electronics and sensors.

Ribbon/Strip: Bimetallic elements, seals, and leadframes for electronic packaging.

Tube/Pipe: Protective tubing for sensors, thermal sleeves, and vacuum system components.

Plate/Sheet: Structural parts for optical systems, heat sinks, and aerospace instrumentation.

In summary, Alloy 475 (Nilo 475 Wire, UNS K95000) — available in forms from Bar and Wire to Plate and Forging Stock — delivers exceptional controlled thermal expansion, mechanical stability, and material compatibility. Its diverse product forms enable tailored solutions across electronics, aerospace, optical, and medical sectors, establishing it as a critical material in applications requiring precision thermal management and dimensional stability.

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 1587 gallon liquid totes Special package is available on request.