Super Invar
Super Invar 32-5
Material Data Sheet
Super Invar 32-5 is a magnetic, austenitic, solid solution alloy containing 32% Nickel, 5% Cobalt, and a balance of Iron. It was designed to provide minimum thermal expansion at room temperatures (one half that of Invar Alloy).
A low coefficient of thermal expansion (CTE) is the most important characteristic of all Invar types and especially of Super Invar. The CTE of Super Invar is around one third the CTE of regular Invar and is almost zero after specific heat processing.
This alloy also exhibits austenite stability to a service temperature of at least -67°F and thermal expansion properties besting Invar alloys when used in the 67/203°F (-55/95°C) temperature range. The minimal expansion of Super Invar over this range of temperatures makes this alloy useful in many applications including structural components and substrates in instrument systems requiring precision measurements.
| Element | Content % |
|---|---|
| Iron, Fe | 63.0 |
| Nickel, Ni | 36.0 |
| Manganese, Mn | 0.35 |
| Silicon, Si | 0.20 |
| Carbon, C | 0.02 |
| Properties | Metric | Imperial |
|---|---|---|
| Density | 8.12 g/cc | 0.294 lb/in3 |
| Specific Gravity | 8.15 | 8.15 |
| Curie Temp | 245 °C | 470 °F |
| Melting Point | 1427 °C | 2600 °F |
| Electrical Resistivity | 82 mΩ-cm | 481 circular mil·Ω/ft |
| Thermal Conductivity | 0.10 W/cm °C | 72.6 BTU-in/sq. ft-hr- |
| Specific Heat | 0.12 Cal/g-°C | 0.12 BTU/lbm- °F |
| Thermal Expansion | 8.0 ppm/°C (25°C to 450°C) | 4.5 ppm/°F(75°F to 842°F) |
| Properties | Metric | Imperial |
|---|---|---|
| Hardness, Rockwell B | 75 | 75 |
| Tensile Strength, Ultimate | 483 MPa | 70000 psi |
| Tensile Strength, Yield | 276 MPa | 40000 psi |
| Elongation at Break | 40% | 40% |
| Modulus of Elasticity | 145 GPa | 21000 ksi |
| Poissons Ratio | 0.23 | 0.23 |
| Machinability | 25% | 25% |
| Shear Modulus | 58.9 GPa | 8540 ksi |
- Structural components for supports
- Substrates in optical and laser systems
- Wave guide tubes
- Telescopes
- Ring laser gyroscopes
- Laser benches
- Positioning devices
- Metrology devices
- Low expansion glass/quartz assemblies
- MIL-I-23011
- AMS-I-23011
- ASTM-F-1684
Key Words:UNS K93601; ASTM B753 Alloy T36
