FeSiAl Powder Core Coated by Ba-B-P-O System Insulating Layer

Sendust soft magnetic composites coated by a thin Ba-B-P-O system insulating layer were produced; SEM spectroscopy and Energy dispersive X-ray analysis spectroscopy confirmed that thin layers of Ba-B-P-O system covered the alloy powders. The influence of various compaction pressures on composites permeability, DC properties and total loss was investigated. The Fe-Si-Al magnetic powder core with compaction pressure of 1932MPa, annealing temperature of 953K with a permeability of 94, a total loss of 108 mW/cm3.

Research on Preparation and Properties of Fe-Si-Al Soft Magnetic Composites

The Fe-Si-Al soft magnetic composites were produced by cold pressing of water-atomized Fe-Si-Al powder using organic binder. The effect of shaping pressure, annealing temperature, magnetic annealing and dielectric content on properties of Fe-Si-Al soft magnetic composites was investigated. The results showed that increasing shaping pressure increases density and radial crushing strength of Fe-Si-Al soft magnetic cores, and decreases coercivity and total loss. Increasing annealing temperature can increase effective permeability and decrease total loss owing to decreasing hysteresis loss, and over-annealing (＞660°C) can deteriorate magnetic properties. The magnetic annealing can decrease total loss of Fe-Si-Al magnetic powder core. Increasing dielectric content can reduce the eddy current loss of Fe-Si-Al magnetic powder core and decrease the real part of permeability. Fe-Si-Al magnetic powder core with shaping pressure of 1800 MPa, annealing temperature of 660 °C and dielelctric content of 0.7% presented the optimum magnetic properties with an effective permeability of 127, a total loss of 78mW/cm3 and a radial crushing strength of 18MPa.