Kovar,Rodar Plate,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® Plate (UNS K94610)** #### **1.0 Product Overview** Kovar Plate (commercially known as Rodar Plate), designated as **UNS K94610**, is a nickel‑cobalt‑iron controlled expansion alloy supplied in plate form. This specialized material exhibits a thermal expansion coefficient that closely matches hard glass and ceramic materials, making it indispensable for applications requiring precise dimensional stability and reliable glass-to-metal seals in electronic, aerospace, and precision engineering industries. --- #### **2.0 Chemical Composition (wt%)** | Element | Content (%) | Function | |---------|-------------|----------| | **Ni** | 28.5–29.5 | Controls thermal expansion characteristics | | **Co** | 16.8–17.8 | Provides matching expansion with glass/ceramics | | **Fe** | Balance | Base metal | | **Mn** | 0.20–0.50 | Deoxidizer and sulfur control | | **Si** | 0.10–0.30 | Deoxidizer and fluidity agent | | **C** | ≤ 0.02 | Minimizes carbide formation | | **Al** | ≤ 0.05 | Deoxidizer | | **P, S**| ≤ 0.02 each | Impurity control for improved workability | --- #### **3.0 Physical Properties** | Property | Value (Metric) | Value (Imperial) | Condition | |----------|----------------|------------------|-----------| | Density | 8.36 g/cm³ | 0.302 lb/in³ | RT | | Melting Point | 1440–1460°C | 2624–2660°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 | RT | | 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 Typical Room Temperature Properties (Annealed)** - **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 - **Shear Modulus**: 55 GPa (8.0 ×10⁶ psi) **4.2 Cold Rolled Condition** - **Tensile Strength**: 620–758 MPa (90–110 ksi) - **Yield Strength**: 550–690 MPa (80–100 ksi) - **Elongation**: 12–22% - **Hardness**: 85–100 HRB --- #### **5.0 Product Specifications** **5.1 Standard Plate Dimensions** - **Thickness**: 0.5 mm to 50 mm (0.020" to 2.0") - **Width**: 100 mm to 600 mm (4.0" to 24.0") - **Length**: 500 mm to 2000 mm (20" to 80") - **Thickness Tolerance**: ±0.05 mm for thickness < 3 mm **5.2 Available Conditions** - Hot rolled, annealed, and pickled - Cold rolled, annealed - Ground finish (both sides) - Stress relieved --- #### **6.0 Heat Treatment** - **Full Annealing**: 850–900°C (1560–1650°F) in hydrogen or vacuum atmosphere, hold 30–60 minutes, rapid cool to 400°C then air cool - **Stress Relieving**: 425–540°C (800–1000°F) for 60–90 minutes - **Pre-Sealing Treatment**: 700–800°C in moist hydrogen to develop oxide layer --- #### **7.0 Applications** **7.1 Electronics & Semiconductor** - Microelectronic package bases - Power semiconductor substrates - RF and microwave housing plates - Laser platform mounting plates - Crystal oscillator bases **7.2 Aerospace & Defense** - Satellite structural platforms - Avionics equipment mounting plates - Radar system base plates - Hermetic connector backplanes - Optical bench substrates **7.3 Industrial & Scientific** - Vacuum chamber wall sections - Precision instrument base plates - X-ray equipment mounting plates - Laboratory furnace components - Measurement equipment frames --- #### **8.0 International Standards** | Standard | Organization | Description | |----------|--------------|-------------| | **ASTM F15** | ASTM | Standard Specification for 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 | | **GB/T 15018** | China | Precision Alloy Classification | --- #### **9.0 Fabrication Characteristics** **9.1 Machining** - Good machinability in annealed condition (70% of free-cutting steel) - Recommended tools: Carbide or high-speed steel with positive rake angles - Cutting speed: 25–40 m/min for turning operations - Use soluble oil coolants for improved surface finish **9.2 Forming** - Good cold formability in annealed condition - Minimum bend radius: 2T (where T = thickness) - Can be deep drawn with proper tool design - Stress relieve after severe forming operations **9.3 Welding & Joining** - Excellent weldability using GTAW (TIG) process - Recommended filler: Matching composition Kovar wire - Pre-heat to 200–300°C for thick sections - Post-weld stress relief at 425–540°C --- #### **10.0 Quality Assurance** - **Certification**: EN 10204 3.1/3.2 Inspection Certificates - **Testing**: - Chemical analysis per ASTM E1473 - Mechanical testing per ASTM E8 - Ultrasonic testing per ASTM A578 for thicker plates - Flatness verification per ASTM A568 - **Traceability**: Full material traceability from melt to finished plate - **Surface Quality**: Free from scale, cracks, and injurious imperfections --- Kovar/Rodar Plate (UNS K94610) provides exceptional thermal expansion matching capabilities combined with good mechanical strength and fabrication characteristics. Its unique properties make it the material of choice for critical applications where dimensional stability and reliable sealing with glass or ceramics are required across varying temperature environments.

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 2383 gallon liquid totes Special package is available on request.