Kovar,Rodar Foil,Shim,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® Foil & Shim (UNS K94610)** #### **1.0 Product Overview** Kovar Foil and Shim (commercially known as Rodar Foil and Shim), designated as **UNS K94610**, are thin-gauge product forms of nickel‑cobalt‑iron controlled expansion alloy. These precision-engineered materials maintain the unique thermal expansion characteristics that match hard glass and ceramics, making them ideal for precision spacing, sealing, and thermal management applications in electronics, aerospace, and scientific instruments where exact dimensional stability is critical. --- #### **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 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 | – | --- #### **4.0 Mechanical Properties** **4.1 Foil Properties (Thickness: 0.025–0.125 mm)** - **Tensile Strength**: 480–550 MPa (70–80 ksi) - **Yield Strength (0.2% Offset)**: 350–420 MPa (51–61 ksi) - **Elongation**: 20–30% - **Hardness**: 60–75 HRB **4.2 Shim Properties (Thickness: 0.15–1.50 mm)** - **Tensile Strength**: 520–590 MPa (75–85 ksi) - **Yield Strength**: 380–450 MPa (55–65 ksi) - **Elongation**: 25–35% - **Hardness**: 65–80 HRB --- #### **5.0 Product Specifications** **5.1 Foil Specifications** - **Thickness Range**: 0.025 mm to 0.125 mm (0.001" to 0.005") - **Width Range**: 50 mm to 300 mm (2.0" to 12.0") - **Standard Tolerance**: ±0.0025 mm (±0.0001") - **Surface Finish**: Bright annealed, rolled finish **5.2 Shim Specifications** - **Thickness Range**: 0.15 mm to 1.50 mm (0.006" to 0.060") - **Width Range**: Up to 600 mm (24.0") - **Standard Tolerance**: ±0.01 mm (±0.0004") - **Available Forms**: Plain, pre-cut shapes, custom configurations --- #### **6.0 Manufacturing Processes** **6.1 Production Methods** - Precision cold rolling on Sendzimir mills - Intermediate annealing in hydrogen atmosphere - Surface conditioning and cleaning - Precision slitting and shearing - Continuous quality monitoring **6.2 Quality Control** - 100% thickness verification - Surface defect inspection - Dimensional accuracy checking - Mechanical property testing --- #### **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 - Special fixtures to prevent distortion - Controlled heating and cooling rates - Batch certification for critical applications --- #### **8.0 Applications** **8.1 Electronics & Semiconductor** - Microelectronic package spacer shims - RF component mounting foils - Laser diode heat spreader shims - Crystal oscillator mounting foils - Power device isolation shims **8.2 Aerospace & Defense** - Gyroscope balancing shims - Satellite instrument spacer foils - Avionics thermal management shims - Radar system spacing elements - Optical alignment shims **8.3 Scientific & Industrial** - Vacuum chamber seal shims - Laboratory instrument spacers - Precision measurement shims - Optical mounting foils - Cryogenic equipment spacers --- #### **9.0 International Standards** | Standard | Organization | Description | |----------|--------------|-------------| | **ASTM F15** | ASTM | Iron-Nickel-Cobalt Sealing Alloy | | **ASTM B90** | ASTM | Magnesium-Alloy Sheet and Plate | | **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 & Cutting** - Excellent formability in annealed condition - Can be stamped, blanked, and etched - Suitable for photochemical machining - Laser and water jet cutting compatible **10.2 Joining Methods** - Resistance welding suitable - Laser welding for precision joints - Brazing with silver-based alloys - Adhesive bonding with proper surface preparation **10.3 Surface Treatment** - Pre-oxidation for glass sealing - Electroplating possible with proper preparation - Passivation treatments available - Special coatings for enhanced performance --- #### **11.0 Quality Assurance** **11.1 Testing Requirements** - Dimensional verification - Surface quality inspection - Mechanical property testing - Chemical composition verification - Flatness measurement **11.2 Certification** - Mill Test Certificates per EN 10204 3.1 - Material traceability - Heat treatment certification - Compliance certificates for specific applications --- #### **12.0 Performance Characteristics** **12.1 Thermal Performance** - Excellent thermal expansion match with borosilicate glass - Minimal thermal stress during cycling - Stable dimensional characteristics - Good thermal conductivity for heat spreading **12.2 Mechanical Performance** - Consistent spring characteristics - Good fatigue resistance - Excellent flatness and stability - Reliable long-term performance --- Kovar/Rodar Foil and Shim (UNS K94610) provide exceptional thermal expansion matching capabilities in thin, precision forms, enabling reliable performance in applications requiring exact dimensional stability and thermal compatibility. Their unique combination of properties makes them essential for critical spacing, sealing, and thermal management applications where conventional materials would fail due to thermal mismatch or inadequate precision.

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 2389 gallon liquid totes Special package is available on request.