Alloy 475,Nilo 475 Tube,UNS K95000,E FORU

British Specs:，American Specs:AMS 7718 Bar, Tube and Forgings MIL-N-14411 Comp 3，German Specs:

### **Alloy 475 (Nilo 475) - Tube Product Overview** **Alloy 475**, commercially known as **Nilo 475**, is a nickel-iron-cobalt controlled expansion alloy specifically designed for matched sealing with special hard glasses and certain ceramic materials. The **Tube** form provides precise tubular components for applications requiring exact dimensional control and unique thermal expansion compatibility in critical sealing applications. * **UNS Designation:** **K95000** * **Common Names:** Nilo 475 Tube, Glass Sealing 475 Tube --- #### **1. Chemical Composition** Precisely controlled chemistry ensures consistent thermal expansion properties in tubular form. | Element | Percentage (%) | Role in the Alloy | |:---|:---|:---| | **Nickel (Ni)** | 46.0 - 48.0 | Primary element controlling CTE characteristics | | **Cobalt (Co)** | 24.0 - 26.0 | Modifies thermal expansion properties | | **Iron (Fe)** | Balance | Base structural element | | **Manganese (Mn)** | 0.10 - 0.30 | Enhances tube drawing characteristics | | **Silicon (Si)** | 0.10 - 0.30 | Improves glass/ceramic wetting performance | | **Carbon (C)** | 0.05 max | Limited for optimal ductility in tube forming | | **Sulfur (S)** | 0.02 max | Controlled impurity | | **Phosphorus (P)** | 0.02 max | Controlled impurity | --- #### **2. Physical Properties** Specialized properties optimized for tubular applications and special material sealing. | Property | Value / Condition | Notes | |:---|:---|:---| | **Density** | 8.35 g/cm³ (0.302 lb/in³) | Higher due to cobalt content | | **Melting Point** | ~1445 °C (2635 °F) | | | **Thermal Expansion Coefficient** | 20-300°C: 7.8-8.5 μm/m·°C
20-400°C: 8.2-9.0 μm/m·°C | Unique CTE for special glasses/ceramics | | **Curie Temperature** | ~420 °C (790 °F) | Modified by cobalt addition | | **Thermal Conductivity** | 14.5 W/m·K at 20°C | | | **Electrical Resistivity** | 0.52 μΩ·m at 20°C | | | **Specific Heat** | 0.45 J/g·°C at 20°C | | --- #### **3. Mechanical Properties (Annealed Condition)** **Tube Mechanical Characteristics:** * **Tensile Strength:** 530-600 MPa (77-87 ksi) * **Yield Strength (0.2% Offset):** 290-360 MPa (42-52 ksi) * **Elongation:** 20-30% in 2 inches * **Hardness:** 73-88 HRB * **Modulus of Elasticity:** 158 GPa (22.9 × 10⁶ psi) * **Collapse Pressure:** Varies with diameter-to-wall thickness ratio --- #### **4. Product Specifications & Applications** **Tube Specifications:** * **Diameter Range:** 1.0 mm to 100 mm OD * **Wall Thickness:** 0.1 mm to 5.0 mm * **Length:** Standard 1-4 meters, custom lengths available * **Tolerance:** OD ±0.1 mm (<10 mm), ±0.5% (>10 mm) * **Wall Tolerance:** ±10% standard, ±5% available * **Surface Finish:** 1.6 μm Ra standard, 0.8 μm Ra available **Types Available:** * **Seamless Tube:** For high-integrity applications * **Drawn Tube:** Precision dimensional control * **Welded & Redrawn Tube:** Economical precision tubing * **Pre-oxidized Tube:** Ready for immediate glass sealing * **Special Finished Tube:** For ceramic sealing applications **Primary Applications:** **Electronics & Vacuum Applications:** * **Special Electronic Tube Components:** Anode caps, grid supports for unique glass systems * **Vacuum Feedthroughs:** Hermetic passages for specialized applications * **Microwave Tube Parts:** Specialized cavity resonators and components * **Semiconductor Equipment:** Special gas distribution lines **Industrial & Scientific Applications:** * **Advanced Optical Instrumentation:** Special laser tube housings * **Laboratory Apparatus:** Unique glass-to-metal seal assemblies * **Sensor Protection Tubes:** Specialized thermocouple wells and housings * **Ceramic Sealing Components:** Tube forms for ceramic-to-metal seals **Aerospace & Defense:** * **Special Avionics Packaging:** Hermetic connector sleeves for unique applications * **Satellite Systems:** Space-qualified components with special requirements * **Military Electronics:** Specialized waveguide and housing elements --- #### **5. International Standards** Comprehensive international specifications for tube products. | Standard Type | Standard Number | Title / Specification | |:---|:---|:---| | **ASTM** | **ASTM F15** | Standard Specification for Iron-Nickel Sealing Alloys | | **UNS** | **K95000** | Unified Numbering System Designation | | **AMS** | AMS 7724 | Aerospace Material Specification | | **ASTM** | ASTM B751 | Standard Specification for Nickel Alloy Seamless Tube | | **DIN** | DIN 1745 | Metallic Materials for Glass-to-Metal Seals | | **ISO** | ISO 9711 | Metallic Materials for Glass-to-Metal Seals | --- #### **6. Manufacturing & Processing** **Fabrication Characteristics:** * **Tube Drawing:** Good drawability with proper annealing cycles * **Bending:** Minimum bend radius 2x OD for thin walls, 3x OD for thick walls * **Machining:** Good machinability with carbide tools and adequate cooling * **Welding:** TIG and laser welding suitable with proper procedures **Sealing Preparation:** * **Surface Preparation:** Critical cleaning and surface activation * **Oxide Control:** Controlled pre-oxidation for optimal adhesion * **Thermal Management:** Controlled heating/cooling rates during sealing process * **Sealing Parameters:** 900-1000°C in controlled atmosphere **Quality Control:** * **Dimensional Verification:** OD, wall thickness, and concentricity measurement * **Surface Quality:** Visual and microscopic examination * **Leak Testing:** Helium leak testing to 1 × 10⁻⁹ atm·cc/s * **Metallurgical Quality:** Grain structure and inclusion assessment --- #### **7. Design Considerations** **Wall Thickness Selection:** * **Ultra-Thin Wall (0.1-0.5 mm):** For miniature specialized components * **Thin Wall (0.5-1.5 mm):** For standard specialized applications * **Medium Wall (1.5-3.0 mm):** For structural and pressure applications * **Heavy Wall (3.0-5.0 mm):** For high-pressure and mechanical applications **End Configurations:** * **Plain Cut:** Standard square-cut ends * **Expanded/Reduced Ends:** For special connection requirements * **Flared Ends:** For mechanical joining applications * **Machined Ends:** Precision machined for specific sealing requirements --- **Summary** **Alloy 475 (Nilo 475) Tube (UNS K95000)** provides precision tubular solutions for applications requiring exact dimensional control and reliable sealing with special glasses and certain ceramics. Its unique thermal expansion properties, enhanced by cobalt content, combined with good forming characteristics and consistent quality, make it indispensable for specialized applications in advanced electronics, aerospace, scientific instrumentation, and specialized industrial sectors. The tube form enables the creation of sophisticated hermetic assemblies where precise dimensional control and unique thermal expansion matching are essential. Compliance with **ASTM F15** and other international standards ensures material consistency and performance reliability for demanding specialized applications across multiple high-technology industries.

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 2525 gallon liquid totes Special package is available on request.