Kovar,Nilo-K Sheet,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® / Nilo-K Sheet (UNS K94610)** **1.0 Product Overview** Kovar Sheet (also known as Nilo-K Sheet), designated as **UNS K94610**, is a nickel‑cobalt‑iron controlled expansion alloy supplied in thin sheet form. This precision-engineered material maintains thermal expansion characteristics that closely match hard glass and ceramics, making it ideal for electronic packaging, aerospace components, and precision instruments requiring reliable thermal compatibility and dimensional stability. --- **2.0 Chemical Composition (wt%)** | Element | Content (%) | Primary 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 (30–400°C) | 5.1 ×10⁻⁶/°C | 2.8 ×10⁻⁶/°F | Matching borosilicate glass | | 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**: 520–590 MPa (75–85 ksi) - **Yield Strength (0.2% Offset)**: 350–420 MPa (51–61 ksi) - **Elongation**: 28–38% - **Hardness**: 68–82 HRB - **Modulus of Elasticity**: 138 GPa (20.0 ×10⁶ psi) **4.2 Cold Rolled Condition (¼ Hard)** - **Tensile Strength**: 580–690 MPa (84–100 ksi) - **Yield Strength**: 480–580 MPa (70–84 ksi) - **Elongation**: 18–28% - **Hardness**: 85–98 HRB --- **5.0 Product Specifications** **5.1 Standard Sheet Dimensions** - **Thickness**: 0.1 mm to 3.0 mm (0.004" to 0.125") - **Width**: 100 mm to 600 mm (4.0" to 24.0") - **Length**: 500 mm to 2000 mm (20" to 80") - **Thickness Tolerance**: ±0.02 mm for thickness < 1.0 mm - **Flatness**: 0.2 mm per 300 mm maximum **5.2 Available Conditions & Finishes** - Annealed (soft) - optimal for forming - ¼ Hard, ½ Hard, Full Hard tempers - Cold rolled, annealed, and pickled - Bright annealed finish - Ground finish (one or both sides) --- **6.0 Manufacturing Processes** **6.1 Production Methods** - Precision cold rolling on Sendzimir mills - Intermediate annealing in hydrogen atmosphere - Surface conditioning and cleaning - Slitting and cutting to size - Final inspection and packaging **6.2 Quality Control** - 100% thickness verification - Surface defect inspection - Mechanical property testing - Dimensional accuracy checking - Flatness measurement --- **7.0 Heat Treatment** **7.1 Full Annealing** - **Temperature**: 850–900°C (1560–1650°F) - **Atmosphere**: Hydrogen or vacuum required - **Time**: 20–40 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 - **Atmosphere**: Air or protective atmosphere - **Application**: After forming operations --- **8.0 Applications** **8.1 Electronics & Semiconductor Packaging** - IC package lids and bases - Microelectronic substrate plates - RF/Microwave housing covers - Power device mounting sheets - Optoelectronic package frames **8.2 Aerospace & Defense Systems** - Satellite electronic housing sheets - Avionics equipment shielding - Radar component substrates - Hermetic connector components - Military electronic enclosure parts **8.3 Scientific & Industrial Instruments** - Vacuum system flange plates - Laser equipment mounting sheets - X-ray window frames - Precision instrument bases - Laboratory equipment components --- **9.0 International Standards & Specifications** | 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 Machining** - Good machinability in annealed condition - Use carbide tools with positive rake angles - Recommended cutting speed: 30–45 m/min - Use soluble oil coolants for improved finish - Suitable for milling, drilling, and turning **10.2 Forming & Stamping** - Excellent formability in annealed condition - Minimum bend radius: 1T (where T = thickness) - Suitable for deep drawing operations - Can be stamped and blanked effectively **10.3 Welding & Joining** - Excellent weldability using GTAW process - Recommended filler: Matching Kovar wire - Pre-heat not required for thin sheets - Post-weld stress relief recommended **10.4 Glass Sealing** - Pre-oxidize at 700–800°C in moist atmosphere - Clean surfaces essential before sealing - Compatible with borosilicate glasses - Forms strong, hermetic bonds --- **11.0 Quality Assurance** **11.1 Testing & Certification** - Chemical composition verification - Mechanical property testing - Surface quality inspection - Dimensional accuracy verification - Flatness measurement **11.2 Documentation** - Mill Test Certificates per EN 10204 3.1 - Full material traceability - Heat treatment certification - Compliance certificates --- **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 for heat spreading **12.2 Fabrication Advantages** - Consistent mechanical properties - Excellent surface finish - Good spring characteristics in hardened tempers - Reliable long-term performance Kovar/Nilo-K Sheet (UNS K94610) provides exceptional thermal expansion matching capabilities in thin sheet form, enabling the manufacture of complex components requiring exact dimensional stability and thermal compatibility. Its unique combination of properties makes it particularly valuable for applications where weight savings, complex geometries, and reliable performance across temperature variations are essential requirements in electronic, aerospace, and precision instrumentation industries.

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 2371 gallon liquid totes Special package is available on request.