Kovar,Alloy K Pipe,UNS K94610,E FORU

British Specs:，American Specs: ASTM F15 ASTM F26 AMS 7726 Wire AMS 7727 Bar and Forgings AMS 7728 Sheet, Strip and Plate MIL-I-23011 Class 1，German Specs:WS 1.3981,AFNOR NF A54-301

**Technical Data Sheet: Kovar® / Alloy K Pipe (UNS K94610)** **1.0 Product Overview** Kovar Pipe (Alloy K Pipe), designated as **UNS K94610**, is a nickel‑cobalt‑iron alloy manufactured in tubular form with a controlled thermal expansion coefficient designed to match hard glass (such as borosilicate) and certain ceramics. This unique property allows the alloy to form reliable hermetic seals in high‑temperature and vacuum environments, making it a critical material in electronics, aerospace, and precision instrument industries. --- **2.0 Chemical Composition (wt%)** | Element | Content (%) | Function | |---------|-------------|----------| | **Ni** | 28.5–29.5 | Controls thermal expansion | | **Co** | 16.8–17.8 | Matches glass/ceramic expansion | | **Fe** | Balance | Base metal | | **Mn** | 0.20–0.50 | Deoxidizer | | **Si** | 0.10–0.30 | Deoxidizer | | **C** | ≤ 0.02 | Minimizes carbide formation | | **Al** | ≤ 0.05 | Deoxidizer | | **P, S**| ≤ 0.02 each | Impurity control | --- **3.0 Physical Properties** | Property | Value (Metric) | Value (Imperial) | Condition | |----------|----------------|------------------|-----------| | Density | 8.36 g/cm³ | 0.302 lb/in³ | RT | | Melting Point | ~1450°C | ~2640°F | – | | Thermal Conductivity | 17.3 W/m·K | 120 Btu·in/(hr·ft²·°F) | 20°C | | Mean CTE | 4.9–5.5 ×10⁻⁶/°C | 2.7–3.1 ×10⁻⁶/°F | 20–400°C | | Electrical Resistivity | 0.49 μΩ·m | 19.0 μΩ·in | 20°C | | Modulus of Elasticity | 138 GPa | 20.0 ×10⁶ psi | RT | | Curie Temperature | 435°C | 815°F | – | --- **4.0 Mechanical Properties** **4.1 Typical Properties (Annealed Condition)** - **Tensile Strength**: 517–586 MPa (75–85 ksi) - **Yield Strength (0.2% Offset)**: 345–414 MPa (50–60 ksi) - **Elongation**: 25–35% - **Hardness**: 65–80 HRB **4.2 Cold Worked Condition** - **Tensile Strength**: 586–758 MPa (85–110 ksi) - **Yield Strength**: 483–620 MPa (70–90 ksi) - **Elongation**: 10–20% --- **5.0 Product Specifications & Sizes** **5.1 Available Forms & Dimensions** - **Outside Diameter**: 3 mm to 120 mm (0.125" to 4.0") - **Wall Thickness**: 0.5 mm to 10 mm (0.020" to 0.375") - **Length**: Up to 6000 mm (240") - **Tolerances**: Per ASTM B774 for seamless thin‑wall tubing **5.2 Manufacturing Methods** - Seamless cold drawing - Welded & redrawn (WR) - Annealed in hydrogen or vacuum atmosphere --- **6.0 Heat Treatment** - **Annealing**: 850–900°C (1560–1650°F) in H₂ or vacuum, followed by rapid cooling to 400°C then air cooling. - **Stress Relieving**: 425–540°C (800–1000°F) for 30–60 minutes. --- **7.0 Applications** - **Electronics & Semiconductors**: - Glass-to-metal seal headers - Microwave tube envelopes - X-ray tube housings - Laser and optoelectronic packages - **Aerospace & Defense**: - Waveguide components - Satellite housing tubes - Hermetic connector shells - **Industrial & Scientific**: - Vacuum furnace components - Cryogenic transfer lines - Precision instrument housings --- **8.0 International Standards** | Standard | Organization | Description | |----------|--------------|-------------| | **ASTM F15** | ASTM | Iron-Nickel-Cobalt Sealing Alloy | | **ASTM B774** | ASTM | Thin-Wall Seamless Pipe & Tube | | **UNS K94610** | ASTM | Unified Numbering System | | **DIN 1.3981** | DIN | German Material Number | | **AMS 7724** | SAE | Bar, Rod, and Wire Forms | | **MIL-I-23011** | U.S. Military | Sealing Alloys | --- **9.0 Fabrication Notes** - **Machining**: Use sharp tools, positive rake; moderate speeds with coolant. - **Welding**: GTAW (TIG) preferred; pre‑clean and use matching filler. - **Glass Sealing**: Pre-oxidize surface to promote glass wetting. - **Brazing**: Suited for silver‑based brazing alloys in controlled atmospheres. --- **10.0 Quality Assurance** - Certification to **EN 10204 3.1** - Hydrostatic/eddy current testing - Dimensional and surface inspection - Thermal expansion testing available upon request Kovar Pipe (UNS K94610) provides exceptional thermal expansion matching, making it indispensable for applications where glass, ceramic, and metal must be joined without inducing stress over repeated thermal cycles.

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 2355 gallon liquid totes Special package is available on request.