Gas-atomized sendust (Fe-9.6Si-5.4Al) powder for 26-125µ power cores. 1.05T saturation, low loss to 200 kHz, certified lot core-loss data. EV charger and solar inductor grades.
QUICK ANSWER
FeSiAl sendust powder is an iron-silicon-aluminum soft magnetic alloy (typically 85% Fe, 9.6% Si, 5.4% Al) gas-atomized into spherical powder and pressed with insulation coating into toroidal and shaped cores. It delivers high saturation flux density (1.0-1.05 T) with near-zero magnetostriction and low core loss, making it the standard material for power factor correction chokes, output inductors, and EV onboard charger magnetics.
Sendust's composition sits at a metallurgical sweet spot where both magnetostriction and magnetocrystalline anisotropy approach zero simultaneously — the origin of its soft magnetic excellence. Compared with pure iron powder cores it cuts core loss dramatically at frequencies above 20 kHz; compared with ferrite it carries three times the flux density, shrinking inductor size. Gas atomization gives the spherical, smooth-surface particles that insulate uniformly and press to high density — powder morphology directly determines core loss in the finished component.
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 |
|---|---|---|
| Iron (Fe) | Balance (~85 wt%) | Magnetic base providing high saturation flux density |
| Silicon (Si) | 9.6 wt% | Raises resistivity, cuts eddy loss; at 9.6% drives anisotropy toward zero |
| Aluminum (Al) | 5.4 wt% | At 5.4% drives magnetostriction toward zero — the sendust sweet spot |
| Oxygen (O) | < 500 ppm | Low oxygen preserves permeability and reduces loss |
| Carbon + others | < 0.05 wt% | Impurity control for magnetic softness |
Final limits can be aligned with the agreed purchase specification.
APPLICATIONS
Power conversion magnetics are the defining market: PFC chokes in server power supplies, output inductors in solar inverters, filter chokes in EV onboard chargers, and DC-DC inductors across industrial electronics are pressed from sendust cores. The distributed air gap formed by the insulated particles gives a soft, saturating characteristic ideal for chokes carrying DC bias — where ferrite would saturate abruptly. Core manufacturers buy the powder on loss performance at specified frequency and flux, particle size distribution consistency, and insulation compatibility.
The EV and renewable energy buildout is driving demand sharply upward: every onboard charger, DC fast-charging station, and string inverter consumes sendust or similar alloy cores, and the shift to higher switching frequencies favors powder cores over laminations. Emerging uses include molded inductors for automotive electronics and integrated magnetics for GaN/SiC converters, where sendust's frequency capability meets the new wide-bandgap switching speeds.
SOFT MAGNETIC & MAGNETIC MATERIAL POWDERS
CUSTOM SUPPLY
We supply gas-atomized sendust powder in standard permeability-grade size distributions with certified low loss and oxygen content, plus FeSi, FeNi, and amorphous alternatives for comparison. Custom size cuts for molded inductor compaction, phosphated or inorganic-coated insulation-ready grades, and core-loss data per lot (at 50 kHz/100 mT or your test condition) are standard. Not export-controlled.
We supply gas-atomized sendust powder in standard permeability-grade size distributions with certified low loss and oxygen content, plus FeSi, FeNi, and amorphous alternatives for comparison.
Custom size cuts for molded inductor compaction, phosphated or inorganic-coated insulation-ready grades, and core-loss data per lot (at 50 kHz/100 mT or your test condition) are standard.
MATERIAL COMPARISON
| Comparison Point | This Product | Iron Powder |
|---|---|---|
| Core loss at 50 kHz | Low | 3-5x higher |
| Saturation flux density | 1.0-1.05 T | 1.3-1.5 T — higher |
| Cost | Moderate | Lowest |
| DC bias capability | Good | Good |
| Frequency range | To 200+ kHz | Below ~20 kHz economical |
| Best use | PFC, mid-frequency chokes | Low-frequency, cost-driven chokes |
TECHNICAL FAQ
Need a different chemistry, particle range, or processing route? Our material team can review the requirement and supply window.
Lower permeability (26-60 µ) gives better DC bias and lower loss for high-current chokes; higher permeability (90-125 µ) suits lower-current filter applications. The permeability comes from particle size and insulation thickness — we supply powder matched to your target grade.
Yes — the Curie point near 500 °C gives wide margin, and core loss actually decreases slightly with temperature. Insulation binder rating, not the alloy, sets the practical limit.
Smooth spherical particles insulate uniformly with thin coating, raising density and lowering hysteresis loss; irregular particles need thicker insulation and trap more air gap, raising loss. Our gas-atomized powder is specified on sphericity for exactly this reason.
We supply insulation-ready powder with surface condition matched to phosphating or inorganic coating processes; fully coated powder on request for customers without in-house coating lines.
No. Iron-silicon-aluminum soft magnetic powder ships without licensing requirements.
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