1J79 Permalloy Alloy Specification
High-Permeability Nickel-Iron Soft Magnetic Alloy for Precision Applications
Product Specification
| Standard | GB/T 15018 (China), ASTM A753 (USA) |
| Material Designation | 1J79 (Fe-Ni-Mo), Permalloy 79 |
| Tolerance | h7-h11 (on request) |
| Melt Method | Vacuum Induction Melting (VIM) |
| Available Forms & Sizes | Strip/Coil: 0.02-1.5mm thick (≤15mm) Wire: φ0.05mm – φ5.0mm Bar: 15-100mm diameter Custom profiles upon request |
Chemical Composition (wt%)
| Element | Min | Max |
| Nickel (Ni) | 78.5 | 80.5 |
| Molybdenum (Mo) | 3.8 | 4.2 |
| Iron (Fe) | Balance | |
| Manganese (Mn) | – | 0.60 |
| Silicon (Si) | – | 0.30 |
| Carbon (C) | – | 0.03 |
| Phosphorus (P) | – | 0.02 |
| Sulfur (S) | – | 0.02 |
Magnetic & Physical Properties
| Property | Value |
| Initial Permeability (μi) | ≥25,000-30,000 mH/m |
| Maximum Permeability (μm) | ≥100,000-110,000 mH/m |
| Coercivity (Hc) | ≤1.2-2.4 A/m |
| Saturation Induction (Bs) | 0.75-0.85 T |
| Resistivity | 55-60 μΩ·cm |
| Density | 8.6 g/cm³ |
| Curie Temperature | 450-460°C |
| Thermal Expansion Coefficient | 9-12×10⁻⁶/°C (20-100°C) |
Applications
- 5G/6G communication base station components (up to 30 GHz)
- High-frequency transformers in switch-mode power supplies
- Magnetic shielding for MRI and electron microscopy
- Precision current transformers and magnetic amplifiers
- Aerospace navigation sensors and satellite components
- High-sensitivity relays and electromagnetic actuators
Special Processing Notes
- Recommended heat treatment: 1100-1150°C/2-4h hydrogen annealing with cooling rate ≤100°C/h
- Cold working deformation should not exceed 20% without intermediate annealing
- Surface polishing or thin-film coating recommended for high-frequency applications
- Store in dry environment to prevent surface oxidation
