Kovar,Rodar Strip,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® Strip (UNS K94610)** #### **1.0 Product Overview** Kovar Strip (commercially known as Rodar Strip), designated as **UNS K94610**, is a nickel‑cobalt‑iron controlled expansion alloy supplied in thin strip form. This precision-engineered material maintains thermal expansion characteristics that closely match hard glass and ceramics, making it ideal for high-volume production of electronic components, hermetic seals, and precision instruments requiring exact dimensional stability across temperature variations. --- #### **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 metal | | **Mn** | 0.20–0.50 | Deoxidizer and improves workability | | **Si** | 0.10–0.30 | Deoxidizer and enhances rolling characteristics | | **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 | – | | 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**: 515–585 MPa (75–85 ksi) - **Yield Strength (0.2% Offset)**: 345–415 MPa (50–60 ksi) - **Elongation**: 30–40% - **Hardness**: 65–80 HRB - **Modulus of Elasticity**: 138 GPa (20.0 ×10⁶ psi) **4.2 Cold Rolled Tempers** | Temper | Tensile Strength | Yield Strength | Elongation | Hardness | |--------|------------------|----------------|------------|----------| | **¼ Hard** | 550–655 MPa | 450–550 MPa | 20–30% | 80–95 HRB | | **½ Hard** | 620–725 MPa | 550–655 MPa | 12–22% | 95–105 HRB | | **Full Hard** | 690–790 MPa | 655–760 MPa | 5–15% | 100–110 HRB | --- #### **5.0 Product Specifications** **5.1 Standard Strip Dimensions** - **Thickness**: 0.05 mm to 2.0 mm (0.002" to 0.080") - **Width**: 2 mm to 300 mm (0.080" to 12.0") - **Coil Weight**: Up to 500 kg (1100 lbs) - **Thickness Tolerance**: ±0.005 mm for thickness < 0.5 mm - **Width Tolerance**: ±0.02 mm for widths < 50 mm **5.2 Available Conditions & Finishes** - Annealed (dead soft) - ¼ Hard, ½ Hard, Full Hard tempers - Bright annealed surface - Cold rolled finish - Special edge conditions (slit, sheared, deburred) --- #### **6.0 Manufacturing Processes** **6.1 Production Methods** - Precision cold rolling on multi-stand mills - Intermediate annealing in hydrogen atmosphere - Precision slitting to width specifications - Surface conditioning and cleaning - Continuous quality monitoring **6.2 Quality Control** - Continuous thickness monitoring - Surface defect detection - Width and edge quality control - Mechanical property testing - Coil quality inspection --- #### **7.0 Heat Treatment** **7.1 Full Annealing** - Temperature: 850–900°C (1560–1650°F) - Atmosphere: Hydrogen or vacuum required - Time: 15–30 minutes at temperature - Cooling: Rapid cool to 400°C, then air cool **7.2 Stress Relieving** - Temperature: 425–540°C (800–1000°F) - Time: 20–40 minutes - Atmosphere: Air or protective atmosphere - Application: After severe forming operations --- #### **8.0 Applications** **8.1 Electronic Components** - Lead frame substrates - IC package lids and covers - Transistor mounting strips - Microelectronic connector elements - RF shield components **8.2 Sealing Applications** - Glass-to-metal seal ribbons - Ceramic package sealing frames - Hermetic connector elements - Optical window mounting strips - Vacuum feedthrough components **8.3 Precision Instruments** - Scale and encoder strips - Precision spring elements - Instrument frame components - Optical mounting strips - Laboratory equipment parts --- #### **9.0 International Standards** | Standard | Organization | Description | |----------|--------------|-------------| | **ASTM F15** | ASTM | Iron-Nickel-Cobalt Sealing Alloy | | **UNS K94610** | ASTM | Unified Numbering System | | **DIN 1.3981** | DIN | German Material Number | | **AMS 7724** | SAE | Bars, Rods, and Wire Forms | | **JIS H 4551** | JIS | Japanese Industrial Standard | | **GB 4J29** | China | Chinese National Standard | --- #### **10.0 Fabrication Characteristics** **10.1 Stamping & Blanking** - Excellent stamping characteristics in annealed condition - Progressive die capability - Clean, burr-free edges - Consistent springback control **10.2 Forming & Bending** - Superior formability in annealed temper - Minimum bend radius: 0.5T (where T = thickness) - Good spring properties in hardened tempers - Suitable for complex formed shapes **10.3 Welding & Joining** - Excellent weldability using resistance welding - GTAW and laser welding suitable - Brazing with silver-based alloys - Epoxy bonding with proper surface preparation **10.4 Etching & Photochemical Machining** - Suitable for photochemical etching - Clean, precise edge definition - Compatible with standard etchants - Good for fine feature reproduction --- #### **11.0 Quality Assurance** **11.1 Testing & Certification** - Chemical composition verification - Mechanical property testing - Surface roughness measurement - Dimensional accuracy verification - Coil quality inspection **11.2 Documentation** - Mill Test Certificates per EN 10204 3.1 - Full material traceability - Statistical process control data - Coil identification and tracking --- #### **12.0 Special Features** **12.1 Thermal Performance** - Excellent expansion match with borosilicate glass - Minimal thermal stress during cycling - Stable dimensional characteristics - Good thermal conductivity **12.2 Manufacturing Advantages** - Consistent gauge control throughout coil length - Uniform mechanical properties - Optimized for high-speed stamping operations - Available in precision slit widths - Custom tempers for specific applications --- Kovar/Rodar Strip (UNS K94610) provides exceptional thermal expansion matching capabilities in precision strip form, enabling high-volume manufacturing of components requiring exact dimensional stability and thermal compatibility. Its combination of consistent quality, excellent fabrication characteristics, and unique thermal properties makes it the material of choice for critical electronic, aerospace, and instrumentation applications where reliability and precision are paramount.

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 2385 gallon liquid totes Special package is available on request.