Alloy 42 is a nickel-iron alloy containing approximately 41% nickel. The alloy is designed to provide thermal expansion characteristics compatible with both hard and soft glasses, making it one of the most widely used materials for lead frames and glass-to-metal sealing applications.
Why Is Alloy 42 Used in Electronic Packaging?
Alloy 42 offers a controlled coefficient of thermal expansion that helps maintain reliable hermetic seals and package integrity. This makes it a preferred material for semiconductor packaging, integrated circuits, and electronic components.
What Is the Chemical Composition of Alloy 42?
| Element |
Composition |
| Nickel (Ni) |
41.0% |
| Manganese (Mn) |
0.2% |
| Carbon (C) |
0.005% |
| Iron (Fe) |
Balance |
What Are the Physical and Mechanical Properties of Alloy 42?
| Property |
Value |
| Density |
0.293 lb/in3 |
| Specific Gravity |
8.12 |
| Tensile Strength |
68,000 psi |
| Yield Strength |
36,000 psi |
| Elongation |
30% |
| Hardness |
125-140 HV |
| Elastic Modulus |
21 × 106 psi |
What Are the Thermal Expansion Properties of Alloy 42?
| Temperature Range |
Thermal Expansion |
| 30-300°C / 86-572°F |
4.0-4.7 × 10-6 m/m/°C |
| 30-450°C / 86-842°F |
6.7-7.4 × 10-6 m/m/°C |
Where Is Alloy 42 Used?
- Semiconductor lead frames
- Integrated circuit packaging
- Electronic housings
- Sensors and relays
- Glass-to-metal seals
- Hermetic packages