Kovar,Rodar Wire,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® / Rodar® Wire (UNS K94610)** #### **1.0 Product Overview** Kovar Wire (commercially known as Rodar Wire), designated as **UNS K94610**, is a nickel‑cobalt‑iron controlled expansion alloy supplied in wire form. This specialized product maintains precise thermal expansion characteristics matching hard glass and ceramics, making it essential for lead frames, electronic interconnects, and sealing applications where reliable thermal compatibility and dimensional stability are required. --- #### **2.0 Chemical Composition (wt%)** | Element | Content (%) | 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 drawability | | **Si** | 0.10–0.30 | Deoxidizer and enhances wire quality | | **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 | 5.1 ×10⁻⁶/°C | 2.8 ×10⁻⁶/°F | 30–400°C | | 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 | – | --- #### **4.0 Mechanical Properties** **4.1 Solution Annealed Condition** - **Tensile Strength**: 480–550 MPa (70–80 ksi) - **Yield Strength (0.2% Offset)**: 300–380 MPa (44–55 ksi) - **Elongation**: 30–40% - **Reduction in Area**: 50–70% - **Hardness**: 60–75 HRB **4.2 As-Drawn Condition** - **Tensile Strength**: 620–790 MPa (90–115 ksi) - **Yield Strength**: 550–690 MPa (80–100 ksi) - **Elongation**: 15–25% - **Hardness**: 85–100 HRB --- #### **5.0 Product Specifications** **5.1 Standard Wire Sizes** - **Diameter Range**: 0.10 mm to 6.0 mm (0.004" to 0.250") - **Diameter Tolerance**: ±0.005 mm for diameters < 1.0 mm - **Spool Weights**: 1 kg to 250 kg (2.2 lb to 550 lb) - **Surface Finish**: Bright, clean, oxide-free **5.2 Available Conditions** - Solution annealed (soft) - Hard drawn (various tempers) - Stress relieved - Special surface finishes available --- #### **6.0 Manufacturing Processes** **6.1 Production Methods** - Hot rolling to rod form - Multi-pass cold drawing with intermediate annealing - Surface conditioning and cleaning - Precision spooling and packaging **6.2 Quality Control** - Continuous diameter monitoring - Surface defect inspection - Mechanical property testing - Spooling quality verification --- #### **7.0 Heat Treatment** **7.1 Standard Treatment** - **Solution Annealing**: 850–900°C (1560–1650°F) in hydrogen atmosphere - **Stress Relieving**: 425–540°C (800–1000°F) for 15–30 minutes - **Cooling**: Rapid cool to 400°C, then air cool **7.2 Special Considerations** - Protective atmosphere essential - Controlled heating and cooling rates - Stress relief after severe drawing operations - Batch certification for critical applications --- #### **8.0 Applications** **8.1 Electronics & Semiconductor** - IC package lead frames - Transistor and diode leads - Microelectronic interconnects - Hybrid circuit bonding wire - Power device internal connections **8.2 Glass & Ceramic Sealing** - Feedthrough pins and leads - Hermetic connector pins - Optical package leads - Vacuum tube elements - Sensor package connections **8.3 Aerospace & Defense** - Satellite electronic interconnects - Avionics component leads - Radar system connections - Military electronic packages - Space-qualified wire applications --- #### **9.0 International Standards** | Standard | Organization | Description | |----------|--------------|-------------| | **ASTM F15** | ASTM | Iron-Nickel-Cobalt Sealing Alloy | | **ASTM F29** | ASTM | Dumet Wire for Glass-to-Metal Seals | | **UNS K94610** | ASTM | Unified Numbering System | | **DIN 1.3981** | DIN | German Material Number | | **AMS 7724** | SAE | Bars, Rods, and Wire Forms | | **MIL-I-23011** | U.S. Military | Sealing Alloys | --- #### **10.0 Fabrication Characteristics** **10.1 Forming & Machining** - Excellent cold forming characteristics - Can be bent, coiled, and shaped - Good machinability in annealed condition - Suitable for automatic forming equipment **10.2 Welding & Joining** - Excellent weldability using resistance methods - GTAW and laser welding suitable - Brazing with silver-based alloys - Thermosonic bonding capability **10.3 Glass Sealing Performance** - Pre-oxidation for optimal glass wetting - Clean surfaces essential before sealing - Compatible with borosilicate glasses - Forms strong, hermetic bonds --- #### **11.0 Quality Assurance** **11.1 Testing Requirements** - Chemical composition verification - Mechanical property testing - Surface quality inspection - Dimensional accuracy checking - Spooling quality assessment **11.2 Certification** - Mill Test Certificates per EN 10204 3.1 - Full material traceability - Heat treatment certification - Compliance with customer specifications --- #### **12.0 Performance Characteristics** **12.1 Thermal Performance** - Excellent thermal expansion match with borosilicate glass - Minimal thermal stress during cycling - Stable dimensional characteristics - Reliable performance across temperature ranges **12.2 Electrical & Mechanical Performance** - Consistent electrical properties - Good spring characteristics in hardened tempers - Excellent fatigue resistance - Reliable long-term performance --- Kovar/Rodar Wire (UNS K94610) provides exceptional thermal expansion matching capabilities in wire form, enabling reliable performance in electronic interconnects, lead frames, and sealing applications where exact dimensional stability and thermal compatibility are critical. Its unique combination of properties makes it essential for applications where conventional materials would fail due to thermal mismatch or inadequate performance characteristics.

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 2390 gallon liquid totes Special package is available on request.