Alloy 48,Nilo 48 Wire,UNS K94800,E FORU

British Specs:，American Specs: ASTM F30，German Specs:

### **Alloy 48 (Nilo 48) - Wire Product Overview** **Alloy 48**, commercially known as **Nilo 48**, is a controlled expansion iron-nickel alloy specifically engineered for matched sealing with hard glasses such as borosilicate and alumina-silicate types. The **Wire** form provides a versatile, continuous length product used primarily as lead-in wires and conductive paths through glass envelopes in electronic components, combining excellent electrical conductivity with precisely matched thermal expansion properties. * **UNS Designation:** **K94800** * **Common Forms:** Round Wire, Flat Wire, Bimetallic Composite Wire --- #### **1. Chemical Composition** Precisely controlled chemistry ensures consistent performance in wire drawing and glass sealing processes. | Element | Percentage (%) | Role in Wire Form | |:---|:---|:---| | **Nickel (Ni)** | 47.5 - 48.5 | Controls thermal expansion characteristics | | **Iron (Fe)** | Balance | Provides structural integrity | | **Manganese (Mn)** | 0.10 - 0.30 | Enhances drawability and surface quality | | **Silicon (Si)** | 0.10 - 0.30 | Improves glass wetting and oxidation resistance | | **Carbon (C)** | 0.05 max | Minimized for maximum ductility | | **Sulfur (S)** | 0.02 max | Controlled for wire drawing performance | | **Phosphorus (P)** | 0.02 max | Controlled for ductility | --- #### **2. Physical Properties** Optimized properties for wire processing and hard glass sealing applications. | Property | Value / Condition | Notes | |:---|:---|:---| | **Density** | 8.22 g/cm³ (0.297 lb/in³) | | | **Melting Point** | ~1430 °C (2605 °F) | | | **Diameter Range** | 0.05 mm to 3.0 mm | Standard round wire | | **Thermal Expansion Coefficient** | 20-300°C: 8.5-9.2 μm/m·°C
20-400°C: 9.0-9.7 μm/m·°C | Matches hard glass expansion | | **Electrical Resistivity** | 0.48 μΩ·m at 20°C | | | **Curie Temperature** | ~480 °C (895 °F) | Critical for CTE matching | | **Surface Finish** | 0.2-0.8 μm Ra | Optimized for glass adherence | --- #### **3. Mechanical Properties** Properties vary with diameter and temper condition. | Diameter (mm) | Temper | Tensile Strength (MPa) | Elongation (%) | Notes | |:---|:---|:---|:---|:---| | 0.05-0.2 | Annealed | 480-550 | 15-25 | Fine wire | | 0.2-0.5 | Annealed | 500-570 | 25-35 | Standard lead wire | | 0.5-1.0 | Annealed | 510-580 | 30-40 | General purpose | | 1.0-3.0 | Annealed | 510-580 | 35-45 | Heavy duty | | All | Hard Drawn | 700-900 | 5-15 | For spring applications | --- #### **4. Product Forms & Specific Applications** **Wire Configurations:** * **Round Wire:** Standard diameters from 0.05 mm to 3.0 mm * **Flat Wire:** Rectangular cross-sections for specialized applications * **Bimetallic Wire:** Copper-clad for improved solderability * **Pre-oxidized Wire:** Ready for immediate glass sealing * **Spool Packaging:** Various spool sizes from 100g to 25kg **Primary Applications:** * **Lead-in Wires:** Electrical conductors through hard glass envelopes in vacuum tubes and specialty lighting * **Semiconductor Packages:** Internal lead frames and connection wires * **Electronic Components:** Resistor, capacitor, and inductor lead wires for high-reliability applications * **Thermocouple Wires:** For high-temperature applications requiring hard glass insulation * **Medical Devices:** Implantable device leads and sensor connections * **Aerospace Electronics:** Critical wiring in avionics and satellite systems * **Glass-Sealed Feedthroughs:** Single and multi-pin configurations for hard glass --- #### **5. International Standards** Compliance with international wire and sealing alloy specifications. | Standard Type | Standard Number | Title / Specification | |:---|:---|:---| | **ASTM** | **ASTM F15** | Standard Specification for Iron-Nickel Sealing Alloys | | **ASTM** | ASTM B258 | Standard Specification for Standard Nominal Diameters of Wire | | **IEC** | IEC 60404-8-6 | Metallic Magnetic Materials Specification | | **MIL-SPEC** | MIL-DTL-23488 | Sealing Alloy Requirements | | **JIS** | JIS H 4541 | Alloy Wires for Glass-to-Metal Seals | | **DIN** | DIN 1745 | Metallic Materials for Glass-to-Metal Seals | | **ISO** | ISO 9711 | Glass-to-Metal Sealing Materials | --- #### **6. Manufacturing & Processing** **Wire Drawing Process:** * Multiple-pass drawing with intermediate annealing * Controlled reduction ratios for optimal grain structure * Final annealing in protective atmosphere * Precision spooling with tension control **Surface Treatments:** * **Copper Plating:** 0.5-2.0 μm thickness for improved solderability * **Nickel Plating:** For high-temperature applications * **Pre-oxidation:** Controlled oxide layer for immediate glass sealing * **Bright Annealing:** For critical surface-sensitive applications **Processing Guidelines:** * **Bending:** Excellent formability in annealed condition * **Welding:** Suitable for resistance, TIG, and laser welding * **Glass Sealing:** Optimal at 900-1050°C with controlled atmosphere * **Straightening:** Capable of precision straightening for automated assembly --- #### **7. Quality Assurance** * **Dimensional Control:** ±2% diameter tolerance standard, ±1% available * **Surface Quality:** 100% visual or automated inspection * **Mechanical Testing:** Regular tensile and elongation verification * **Metallurgical Quality:** Grain size control (ASTM 6-8 typical) * **Certification:** Full material traceability with test reports --- **Summary** **Alloy 48 (Nilo 48) Wire (UNS K94800)** provides a critical connection solution for applications requiring reliable electrical conduction through hard glass seals. Its precisely matched thermal expansion properties with borosilicate and other hard glasses, combined with excellent electrical characteristics and formability, make it indispensable for the lighting, electronics, aerospace, and medical device industries. The wire's ability to maintain hermetic integrity while providing electrical connectivity through hard glass envelopes has established it as a fundamental material in high-reliability electronic packaging and component manufacturing. Compliance with **ASTM F15** and other international standards ensures consistent quality and performance for both high-volume production and specialized custom applications requiring matched sealing with hard glasses.

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 2507 gallon liquid totes Special package is available on request.