Kovar,Nilo-K Rod,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® / Nilo-K Rod (UNS K94610)** **1.0 Product Overview** Kovar Rod (also known as Nilo-K Rod), designated as **UNS K94610**, is a nickel‑cobalt‑iron controlled expansion alloy supplied in rod form. This specialized product maintains precise thermal expansion characteristics matching hard glass and ceramics, making it ideal for machining components requiring reliable thermal compatibility in electronic packaging, aerospace systems, and scientific instruments. --- **2.0 Chemical Composition (wt%)** | Element | Content (%) | Primary Function | |---------|-------------|------------------| | **Ni** | 28.5–29.5 | Controls thermal expansion coefficient | | **Co** | 16.8–17.8 | Fine-tunes expansion match with glass/ceramics | | **Fe** | Balance | Base element | | **Mn** | 0.20–0.50 | Deoxidizer and improves machinability | | **Si** | 0.10–0.30 | Deoxidizer and enhances hot workability | | **C** | ≤ 0.02 | Minimizes carbide formation | | **Al** | ≤ 0.05 | Deoxidizer | | **P** | ≤ 0.02 | Impurity control | | **S** | ≤ 0.02 | Impurity control | --- **3.0 Physical Properties** | Property | Value (Metric) | Value (Imperial) | Condition | |----------|----------------|------------------|-----------| | Density | 8.36 g/cm³ | 0.302 lb/in³ | 20°C | | Melting Range | 1440–1460°C | 2624–2660°F | – | | Thermal Conductivity | 17.3 W/m·K | 120 Btu·in/(hr·ft²·°F) | 20°C | | Mean CTE (30–400°C) | 5.1 ×10⁻⁶/°C | 2.8 ×10⁻⁶/°F | Matching borosilicate glass | | Electrical Resistivity | 0.49 μΩ·m | 19.0 μΩ·in | 20°C | | Modulus of Elasticity | 138 GPa | 20.0 ×10⁶ psi | 20°C | | Curie Temperature | 435°C | 815°F | – | | Specific Heat | 0.46 J/g·°C | 0.11 Btu/lb·°F | 20°C | --- **4.0 Mechanical Properties** **4.1 Annealed Condition (Typical)** - **Tensile Strength**: 520–590 MPa (75–85 ksi) - **Yield Strength (0.2% Offset)**: 350–420 MPa (51–61 ksi) - **Elongation**: 25–35% - **Reduction in Area**: 45–60% - **Hardness**: 68–82 HRB - **Modulus of Elasticity**: 138 GPa (20.0 ×10⁶ psi) **4.2 Cold Drawn Condition** - **Tensile Strength**: 620–760 MPa (90–110 ksi) - **Yield Strength**: 550–690 MPa (80–100 ksi) - **Elongation**: 15–25% - **Hardness**: 85–100 HRB --- **5.0 Product Specifications** **5.1 Standard Rod Sizes** - **Diameter Range**: 1.0 mm to 150 mm (0.040" to 6.0") - **Length**: 1000 mm to 3000 mm (39" to 118") - **Diameter Tolerance**: h9 for precision applications - **Straightness**: 1 mm per 300 mm maximum - **Surface Finish**: Centerless ground, turned, or as-drawn **5.2 Available Conditions** - Annealed (soft condition) - optimal for machining - Centerless ground - precise dimensions - Cold drawn - improved surface finish - Turned and polished - special applications --- **6.0 Manufacturing Processes** **6.1 Production Methods** - Hot rolling from forged billets - Cold drawing for improved surface finish - Centerless grinding for tight tolerances - Annealing in hydrogen or vacuum atmosphere **6.2 Quality Control** - Ultrasonic testing for internal quality - Dimensional verification - Surface quality inspection - Mechanical property testing --- **7.0 Heat Treatment** **7.1 Solution Annealing** - **Temperature**: 850–900°C (1560–1650°F) - **Atmosphere**: Hydrogen or vacuum required - **Time**: 30–60 minutes at temperature - **Cooling**: Rapid cool to 400°C, then air cool **7.2 Stress Relieving** - **Temperature**: 425–540°C (800–1000°F) - **Time**: 30–60 minutes - **Atmosphere**: Air or protective atmosphere - **Application**: Recommended after heavy machining --- **8.0 Applications** **8.1 Electronic Components** - Semiconductor lead frames and pins - IC package structural components - Microwave tube elements - Power device mounting studs - Vacuum feedthrough conductors **8.2 Aerospace & Defense** - Satellite structural members - Avionics mounting pins - Radar waveguide supports - Gyroscope components - Military electronic package parts **8.3 Scientific Instruments** - Electron microscope components - Laser system mounting rods - Vacuum system structural elements - Precision instrument shafts - Laboratory equipment frames --- **9.0 International Standards & Specifications** | Standard | Organization | Description | |----------|--------------|-------------| | **ASTM F15** | ASTM | Iron-Nickel-Cobalt Sealing Alloy | | **AMS 7724** | SAE | Bars, Rods, and Wire Forms | | **UNS K94610** | ASTM | Unified Numbering System | | **DIN 1.3981** | DIN | German Material Number | | **JIS H 4551** | JIS | Japanese Industrial Standard | | **GB 4J29** | China | Chinese National Standard | --- **10.0 Machining & Fabrication** **10.1 Machining Guidelines** - Good machinability in annealed condition - Use carbide tools with positive rake angles - Recommended cutting speed: 25–40 m/min - Use soluble oil coolants for optimal finish - Moderate work hardening tendency **10.2 Turning Operations** - **Roughing**: Depth of cut 2–4 mm, feed 0.2–0.4 mm/rev - **Finishing**: Depth of cut 0.5–1.0 mm, feed 0.1–0.2 mm/rev - **Surface Speed**: 30–45 m/min for carbide tools **10.3 Drilling & Tapping** - Use HSS or carbide drills with 118° point angle - Peck drilling recommended for deep holes - Tapping requires sharp taps with adequate clearance --- **11.0 Performance Characteristics** **11.1 Thermal Expansion Match** - Excellent compatibility with borosilicate glass (Pyrex) - Matches 96% alumina ceramic expansion - Minimal sealing stress during thermal cycling - Stable performance from cryogenic to elevated temperatures **11.2 Glass Sealing Preparation** - Degrease and clean before sealing operations - Controlled oxidation at 700–800°C for optimal bonding - Surface activation essential for strong seals - Avoid contamination before sealing processes --- **12.0 Quality Assurance** **12.1 Testing & Certification** - Chemical composition analysis - Thermal expansion coefficient verification - Mechanical property testing - Ultrasonic testing for critical applications - Dimensional accuracy certification **12.2 Documentation** - Mill Test Certificates per EN 10204 3.1 - Full material traceability - Heat treatment records - Compliance with customer specifications Kovar/Nilo-K Rod (UNS K94610) provides manufacturers with a versatile raw material for producing precision components that require exact thermal expansion matching with glass and ceramics. The rod form enables cost-effective production of complex parts through machining while maintaining the unique thermal properties essential for reliable glass-to-metal and ceramic-to-metal seals in demanding electronic, aerospace, and scientific applications.

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 2366 gallon liquid totes Special package is available on request.