Alloy 46,Glass sealing 46 Alloy ,UNS K94600

Alloy 46,Glass sealing 46 Alloy Wire,UNS K94600

Alloy 46 (Glass Sealing 46 Alloy Wire, UNS K94600) - Introduction with Composition, Properties, Applications and Product Forms

Alloy 46, commercially referred to as Glass Sealing 46 Alloy and designated by UNS K94600, is a nickel-iron alloy renowned for its precise thermal expansion characteristics, making it a pivotal material in glass-to-metal sealing applications. This alloy is specifically engineered to exhibit a coefficient of thermal expansion (CTE) that closely matches a variety of glasses, ensuring the formation of durable, hermetic seals even when subjected to extreme temperature fluctuations. 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. Glass Sealing 46 Alloy Wire, in particular, is valued for its uniform thermal properties, flexibility, and precision, making it ideal for intricate seals, fine wire components, and precision assemblies in electronics, aerospace, and lighting 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 46 (Glass Sealing 46 Alloy, UNS K94600) is the foundation of its exceptional glass-matching thermal expansion and mechanical reliability. The typical composition (by weight) is as follows:

Nickel (Ni): 45-47% (the primary element, responsible for controlling thermal expansion to match glass and enhancing corrosion resistance)

Iron (Fe): 53-55% (balances the alloy, providing structural strength and supporting thermal stability)

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

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

Silicon (Si): ≤ 0.3% (controlled to prevent oxide formation that could compromise glass-to-metal bonding)

Sulfur (S): ≤ 0.01% (strictly limited to ensure good ductility and prevent embrittlement, critical for forming)

Phosphorus (P): ≤ 0.02% (kept low to preserve corrosion resistance and avoid grain boundary weakness)

This carefully engineered nickel-iron blend delivers the alloy's signature thermal expansion characteristics, ensuring compatibility with a range of glasses such as soda-lime, borosilicate, and leaded glasses—key to creating hermetic seals that withstand thermal cycling without cracking.

Key Properties

Alloy 46 (Glass Sealing 46 Alloy Wire, UNS K94600) and its various forms exhibit a unique set of properties that make them indispensable in glass-to-metal sealing and precision thermal applications:

Thermal Expansion Properties:

Coefficient of thermal expansion (CTE):

20-300°C: 7.5-8.5 × 10⁻⁶ /°C (precisely tuned to match a wide range of glasses, minimizing stress in seals during temperature changes)

20-400°C: 8.0-9.0 × 10⁻⁶ /°C (maintains compatibility with glass at moderately elevated temperatures)

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

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

Curie temperature: 430-450°C (the temperature above which ferromagnetic properties diminish)

Mechanical Properties (annealed condition):

Tensile strength: 410-510 MPa (59,500-73,900 psi)

Yield strength (0.2% offset): 140-210 MPa (20,300-30,500 psi)

Elongation (in 50 mm): 28-38% (excellent ductility, enabling forming into fine wires, thin ribbons, and complex seal geometries)

Hardness: 115-155 HB (Brinell hardness, reflecting good machinability and workability for precision components)

Physical and Magnetic Properties:

Density: 8.0-8.2 g/cm³ (0.289-0.296 lb/in³)

Modulus of elasticity: 175-185 GPa (25,400-26,800 ksi) at room temperature

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

Corrosion resistance: Good resistance to atmospheric corrosion, moisture, and mild chemicals, ensuring long-term seal integrity

Sealing Compatibility:

Glass types: Compatible with soda-lime glass, borosilicate glass, and leaded glasses, forming hermetic seals with minimal stress

Seal strength: Maintains bond integrity through thermal cycling (-55°C to 200°C), vibration, and pressure changes, critical for vacuum and pressurized systems

Product Forms

Alloy 46 (Glass Sealing 46 Alloy, UNS K94600) is manufactured in a diverse range of forms to accommodate specialized glass-sealing and precision thermal 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), ideal for machining into seal headers, flanges, and structural components for glass-to-metal assemblies.

Ribbon: Thin, flat strips (thickness 0.01 mm to 0.5 mm, width 1 mm to 100 mm) used in flat seals, electronic packaging, and miniature glass-to-metal connections requiring uniform contact.

Wire: Glass Sealing 46 Alloy Wire (diameters 0.02 mm to 5 mm) offers exceptional uniformity and flexibility, suitable for fine wire seals, thermocouple leads, and wire bonds in vacuum tubes and sensors.

Rods: Solid cylindrical rods (diameters 2 mm to 30 mm) used in pin seals, feedthroughs, and precision glass-mounting components.

Tube and Pipe: Hollow forms (outer diameter 3 mm to 100 mm, wall thickness 0.1 mm to 5 mm) for glass-encased tubing, protective sleeves, and vacuum feedthroughs.

Foil: Ultra-thin sheets (thickness 0.001 mm to 0.1 mm) used in flexible seals, thin-film electronics, and lightweight glass-to-metal laminates.

Plate and Sheet: Flat forms (plate: thickness 1 mm to 20 mm; sheet: 0.05 mm to 1 mm) for fabricating large seals, optical instrument housings, and display panels with glass integration.

Strip: Narrow, flat strips (thickness 0.05 mm to 1 mm, width 2 mm to 100 mm) for precision components such as relay seals, lamp bases, and sensor connectors.

Forging Stock: Billets and ingots for hot forging into custom shapes, such as large flanges and complex seal structures for industrial glass systems.

Applications

The exceptional glass-matching properties and reliability of Alloy 46 (Glass Sealing 46 Alloy Wire, UNS K94600) across its various forms make it a critical material in industries requiring hermetic glass-to-metal seals:

Electronics and Telecommunications:

Vacuum tubes and electron devices: Seal pins, headers, and feedthroughs (from wire, rod, and bar) for vacuum tubes, klystrons, and magnetrons, ensuring airtight operation.

Sensor packaging: Hermetic seals for pressure sensors, temperature sensors, and MEMS devices (from ribbon, wire, and sheet), protecting sensitive electronics from moisture and contaminants.

Connectors and feedthroughs: Glass-sealed electrical connectors (from bar, tube, and strip) for aerospace, marine, and industrial equipment, preventing signal degradation.

Lighting and Optoelectronics:

Lighting components: Seal bases for halogen lamps, high-intensity discharge (HID) lamps, and specialty bulbs (from wire, strip, and rod), ensuring gas-tight enclosures.

Optical fibers: Glass-to-metal seals for fiber optic connectors and feedthroughs (from tube, wire, and ribbon), maintaining light transmission integrity.

Display technology: Seals for OLED panels, LCD backlights, and projection systems (from sheet, foil, and strip), integrating glass and metal components without thermal stress.

Aerospace and Defense:

Avionics: Hermetic seals for radar components, navigation systems, and communication devices (from plate, bar, and tube) operating in extreme environments.

Missile and spacecraft systems: Pressure-tight seals for guidance systems, thermal sensors, and fuel monitoring equipment (from forging stock, rod, and wire).

Military communication: Glass-sealed connectors and feedthroughs (from strip, bar, and tube) for secure radio systems and underwater communication devices.

Medical and Industrial:

Medical devices: Hermetic seals for pacemakers, implantable sensors, and diagnostic equipment (from wire, ribbon, and tube), ensuring biocompatibility and long-term reliability.

Industrial vacuum systems: Seals for vacuum chambers, plasma processing equipment, and semiconductor manufacturing tools (from plate, tube, and bar).

Energy systems: Glass-to-metal seals for batteries, fuel cells, and solar panel components (from sheet, strip, and wire), withstanding thermal cycling and chemical exposure.

Specialized Applications by Form:

Wire: Fine pin seals in microelectronics, thermocouple leads in glass-encased sensors, and wire bonds in vacuum devices.

Ribbon/Strip: Flat seals in batteries, lamp bases, and relay contacts requiring uniform glass contact.

Tube/Pipe: Vacuum feedthroughs, protective sleeves for optical fibers, and gas-tight tubing in analytical instruments.

Plate/Sheet: Large glass-sealed panels for display systems, optical instrument housings, and industrial furnace windows.

In summary, Alloy 46 (Glass Sealing 46 Alloy Wire, UNS K94600) — available in forms from Bar and Wire to Plate and Forging Stock — delivers exceptional glass-matching thermal expansion, hermetic sealing capability, and mechanical reliability. Its diverse product forms enable tailored solutions across electronics, lighting, aerospace, and medical sectors, establishing it as a critical material in applications requiring durable glass-to-metal integration.

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 1540 gallon liquid totes Special package is available on request.