1. Soft Magnetic Alloys
1.1 Permalloy 1J50 / Ni-Fe 50
| Item | Value |
|---|---|
| UNS | K94100 |
| Composition | Ni: 49.0–51.0, Fe: Balance |
| Density | 8.2 g/cm³ |
| Key Properties | High initial permeability, low coercivity, good magnetic response in weak fields |
| Typical Applications | Relay cores, transformer cores, magnetic shielding, sensor components |
1.2 Permalloy 1J79 / Ni-Fe 79
| Item | Value |
|---|---|
| UNS | K94200 |
| Composition | Ni: 78.0–80.0, Mo: 3.5–5.0, Fe: Balance |
| Density | 8.7 g/cm³ |
| Key Properties | Ultra-high permeability, very low coercivity, excellent magnetic shielding |
| Typical Applications | High-sensitivity sensors, precision transformers, magnetic shielding |
2. Low Expansion Alloys
2.1 Invar 36 / Fe-Ni 36
| Item | Value |
|---|---|
| UNS | K93600 |
| Composition | Ni: 35.0–37.0, Fe: Balance |
| Density | 8.1 g/cm³ |
| Thermal Expansion (20–100°C) | ~1.2 × 10⁻⁶ /°C |
| Key Properties | Ultra-low thermal expansion near room temperature |
| Typical Applications | Precision instruments, optical devices, electronic packages, valves |
2.2 Kovar / Fe-Ni-Co 29-17
| Item | Value |
|---|---|
| UNS | K94610 |
| Composition | Ni: 28.0–29.0, Co: 16.0–18.0, Fe: Balance |
| Density | 8.1 g/cm³ |
| Thermal Expansion | Matches borosilicate glass & alumina ceramics |
| Key Properties | Controlled expansion for glass‑to‑metal sealing |
| Typical Applications | Vacuum and electronic tubes, transistor headers, glass‑metal seals |
3. Key Summary
- Soft Magnetic Alloys: High permeability, low coercivity, used for magnetic cores and shielding.
- Expansion Alloys: Low or matched thermal expansion, used for precision parts and glass‑metal sealing.