Expansion Kovar
4J29
Features
4J29 alloy has a matching coefficient of thermal expansion with glass and ceramics, making it suitable for airtight sealing applications.
Applications
- Electron tube casings
- Integrated circuit lead frames
- Vacuum devices
Specifications
-
Plate / Sheet
- Thickness: 0.1mm-20mm
- Width: 50mm-1000mm
- Length: 1000mm-6000mm
-
Strip
- Thickness: 0.02mm-1mm
- Width: 3mm-500mm
- Delivery Forms: Bright shiny surface or anodized surface, supplied in spools or cut-to-length
-
Rod
- Diameter: Ø3mm-Ø100mm
- Length: 100mm-2000mm
- Delivery Forms: Hot rolled, forged or turned
-
Wire
- Diameter: Ø0.03mm-Ø6mm
- Delivery Forms: Bright shiny or anodized, supplied in spools
-
Tube
- Outer Diameter: Ø3mm-Ø200mm
- Wall Thickness: 0.5mm-10mm
- Length: 100mm-6000mm
Chemical Composition
| Elements | 4J29 | |
| Carbon (C) | Not greater than | 0.03 |
| Sulfur (S) | 0.02 | |
| Phosphorus (P) | 0.02 | |
| Manganese (Mn) | ≤0.50 | |
| Silicon (Si) | ≤0.30 | |
| Nickel (Ni) | 28.5-29.5 | |
| Cobalt (Co) | 16.8-17.8 | |
| Iron (Fe) | Rest |
Thermal Expansion Properties
| Alloy Grade | 20°C-100°C | 20°C-300°C | 20°C-500°C |
| 4J29 Kovar Alloy | 4.6×10⁻⁶ /°C | 5.5×10⁻⁶ /°C | 6.2×10⁻⁶ /°C |
Mechanical Properties
| Alloy Grade | 4J29 Kovar Alloy |
| Density (g/cm³) | 8.2 |
| Tensile Strength (MPa) | 600-700 |
| Yield Strength (MPa) | 300-400 |
| Hardness (HV) | 200-250 |
Electrical Properties
| Alloy Grade | 4J29 Kovar Alloy |
| Electrical Resistivity (10⁻⁶ Ω·cm) | 50 |
| Thermal Conductivity (W/m·K) | 16-18 |