Kovar,Alloy 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 / Alloy K Rod (UNS K94610)** **1.0 Product Overview** Kovar Rod (Alloy K Rod), standardized as UNS K94610, is a nickel-cobalt ferrous alloy supplied in rod form, specifically engineered to match the thermal expansion characteristics of hard glass and ceramic materials. This controlled expansion alloy in rod form is ideal for machining precision components that require reliable thermal compatibility with glass and ceramics in electronic, aerospace, and scientific applications. **2.0 Chemical Composition** | Element | Content (%) | Primary Function | |---------|-------------|------------------| | Fe | Balance | Base Element | | Ni | 28.5-29.5 | Thermal Expansion Control | | Co | 16.8-17.8 | Thermal Expansion Matching | | Mn | 0.20-0.50 | Deoxidizer | | Si | 0.10-0.30 | Deoxidizer | | Al | 0.05 max | Deoxidizer | | Mg | 0.05 max | Deoxidizer | | C | 0.02 max | Minimize carbide formation | | P | 0.02 max | - | | S | 0.02 max | - | *Note: The precise balance of nickel and cobalt ensures consistent thermal expansion properties throughout the rod material.* **3.0 Physical Properties** | Property | Metric Value | Imperial Value | Condition | |----------|--------------|----------------|-----------| | Density | 8.36 g/cm³ | 0.302 lb/in³ | Room Temperature | | 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 | Room Temperature | **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% - Reduction in Area: 45-60% - Hardness: 65-80 HRB **4.2 Cold Drawn Properties** - Tensile Strength: 586-689 MPa (85-100 ksi) - Yield Strength: 483-586 MPa (70-85 ksi) - Elongation: 15-25% - Hardness: 80-95 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:** ±0.05 mm for diameters < 10 mm - **Straightness:** 1 mm per 300 mm maximum **5.2 Available Conditions** - Annealed (soft condition) - Centerless ground - Cold drawn - Turned and polished **6.0 Manufacturing Processes** **6.1 Production Methods** - Hot rolling from billets - Cold drawing for precise dimensions - Centerless grinding for tight tolerances - Annealing in controlled atmosphere **6.2 Quality Control** - Ultrasonic testing for internal quality - Dimensional verification - Surface quality inspection - Mechanical property testing **7.0 Heat Treatment** **7.1 Annealing Process** - Temperature: 850-900°C (1560-1650°F) - Atmosphere: Hydrogen or vacuum - 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 - Recommended after heavy machining **8.0 Product Applications** **8.1 Electronic Components** - Lead frames and pin connectors - Semiconductor package leads - Microwave tube components - X-ray tube anodes and supports - Vacuum interrupter contacts **8.2 Aerospace & Defense** - Gyroscope components - Navigation system parts - Satellite communication elements - Radar system components - Hermetic connector pins **8.3 Scientific Instruments** - Laser housing components - Optical mounting systems - Telescope alignment parts - Laboratory equipment frames - Precision instrument bases **9.0 International Standards & Specifications** | Standard Organization | Standard Number | Description | |----------------------|-----------------|-------------| | ASTM | F15 | Iron-Nickel-Cobalt Sealing Alloy | | AMS | 7724 | Rod and Bar Form | | UNS | K94610 | Unified Numbering System | | DIN | 1.3981 | German Material Number | | JIS | H 4551 | Japanese Industrial Standard | **10.0 Machining & Fabrication** **10.1 Machining Guidelines** - Good machinability in annealed condition - Use sharp, positive rake cutting tools - Recommended speed: 30-45 m/min - Use soluble oil coolants - Chip breakers helpful for continuous chips **10.2 Special Considerations** - Moderate work hardening tendency - Requires rigid tooling setup - Good surface finish achievable - Suitable for automatic screw machines **11.0 Glass Sealing Performance** **11.1 Thermal Expansion Match** - Excellent match with borosilicate glass - Compatible with alumina ceramics - Minimal sealing stress - Reliable hermetic seals - Stable through thermal cycling **11.2 Surface Preparation** - Degrease before glass sealing - Controlled oxidation for optimal bonding - Clean, smooth surface essential - Avoid contamination before sealing **12.0 Quality Assurance** **12.1 Testing Requirements** - Chemical composition analysis - Thermal expansion coefficient verification - Mechanical property testing - Ultrasonic testing for critical applications - Surface quality assessment **12.2 Certification** - Mill Test Certificates per EN 10204 3.1 - Full material traceability - Heat treatment certification - Compliance with customer specifications Kovar Rod (Alloy 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. Its availability in rod form enables cost-effective production of complex parts through machining while maintaining the unique thermal properties that have made Kovar essential for reliable glass-to-metal and ceramic-to-metal seals in demanding 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 2353 gallon liquid totes Special package is available on request.