50Ni-50Fe soft magnetic powder for current transformer cores, RCD toroids and magnetic shielding. Spherical and flake forms, Mo-bearing high-µ variants, lot test-ring data.
QUICK ANSWER
FeNi50 is a 50% nickel-50% iron soft magnetic alloy powder (mid-range permalloy) combining high permeability with useful saturation flux density (~1.5 T) — atomized or ground into powder for pressed toroids, molded shielding components, and magnetic flake. It fills the gap between cheap iron cores and expensive 80% nickel permalloy where both sensitivity and flux capacity matter.
Nickel-iron alloys derive their value from the permeability peak near 50-80% Ni, where magnetocrystalline anisotropy passes through zero. FeNi50 trades some of 80-permalloy's extreme permeability for higher saturation and lower cost — the practical choice for current-transformer cores, ground-fault interrupter toroids, magnetic shielding cans pressed from powder, and high-permeability molded components. In powder form it also serves magnetic flake applications in absorption coatings and permeability-tuned composites.
MATERIAL DATA
Lot-level controls focus on the chemistry, particle characteristics, and process values that influence manufacturing consistency and finished-part performance.
| Element | Content | Performance Role |
|---|---|---|
| Nickel (Ni) | 48-52 wt% | Permeability driver — the 50% level balances µ and saturation |
| Iron (Fe) | Balance (~50 wt%) | Magnetic base contributing saturation flux density |
| Molybdenum (Mo) | 0-4 wt% (FeNiMo variants) | Raises permeability and resistivity in supermalloy-type grades |
| Manganese (Mn) | < 0.5 wt% | Deoxidation residue within specification |
| Silicon + C + S + P | < 0.1 wt% combined | Impurity control — magnetic softness is impurity-sensitive |
Final limits can be aligned with the agreed purchase specification.
APPLICATIONS
Current sensing and protection form the volume market: current transformers for energy metering, residual-current (ground fault) interrupter toroids, and precision measurement cores are wound from strip or pressed from FeNi powder where high permeability at low field detects milliamp-level imbalances. The distributed-gap powder core version suits applications carrying DC bias or requiring gapped stability. Buyers are core manufacturers who anneal the pressed parts in hydrogen — they purchase powder on purity, since sulfur, carbon, and oxygen pin domain walls and kill permeability.
Magnetic shielding and absorption form the specialty market: pressed and machined FeNi50 shielding cans protect sensitive sensors, photomultipliers, and quantum devices from ambient fields; FeNi flake loads into paints and composites for electromagnetic absorption. Medical electronics — MRI-adjacent sensors, implantable device magnetics — add a growing qualified niche. These buyers need morphology control (flake aspect ratio, spherical distribution) as much as chemistry.
SOFT MAGNETIC & MAGNETIC MATERIAL POWDERS
CUSTOM SUPPLY
We supply FeNi50 in atomized spherical powder for pressing, milled flake for absorption and shielding composites, and molybdenum-bearing high-permeability variants. Custom Ni levels from 36% (high saturation) to 80% (maximum permeability), hydrogen-anneal-ready purity grades, and lot permeability data on pressed-annealed test rings are available. Not export-controlled.
We supply FeNi50 in atomized spherical powder for pressing, milled flake for absorption and shielding composites, and molybdenum-bearing high-permeability variants.
Custom Ni levels from 36% (high saturation) to 80% (maximum permeability), hydrogen-anneal-ready purity grades, and lot permeability data on pressed-annealed test rings are available.
MATERIAL COMPARISON
| Comparison Point | This Product | FeNi80 Permalloy |
|---|---|---|
| Initial permeability | 20,000-50,000 | 100,000+ — much higher |
| Saturation flux density | ~1.5 T | ~0.8 T — half |
| Nickel cost exposure | Moderate | High |
| DC bias tolerance | Better (higher Bs) | Poor — saturates early |
| Best use | CT cores, shielding with field capacity | Maximum-sensitivity, low-field sensing |
| Strain sensitivity | Moderate | High — handling degrades µ |
TECHNICAL FAQ
Need a different chemistry, particle range, or processing route? Our material team can review the requirement and supply window.
Not fully — the distributed gap from particle insulation lowers effective permeability. Powder cores win where DC bias or gap stability matters; strip wound cores win on raw permeability. We supply both target grades with test-ring data.
Permeability in NiFe alloys is destroyed by parts-per-thousand impurity levels — carbon, sulfur, and oxygen pin domain walls. Our powder is atomized and handled for minimum contamination, with hydrogen anneal recommended to develop final properties.
Yes — milled flake with controlled aspect ratio (typically 30-80:1) for radar-absorbing and permeability-tuned composite formulations.
Typically 1100-1200 °C in dry hydrogen with controlled cooling through the ordering range for 50% alloys. We provide recommended cycles with each lot; Mo-bearing grades need slow cooling for maximum µ.
No. Nickel-iron soft magnetic powders ship without licensing requirements.
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