Production of Fe-Si-Al-Ni-Ti soft magnetic alloy powder by inert-gas atomization

AbstractFe-3%Si-0.5%Al-2%Ni-2%Ti soft magnetic alloy powders were prepared by inert-gas atomization. The composition, phase structure, size distribution, surface morphology and cross-sectional microstructure of the powder were characterized by chemical analysis, X-ray diffractormeter, laser scattering particle size distribution analyzer and electron probe microanalyzer, respectively. The effects of gas atomization pressure and temperature on the powder size and morphologies were also investigated. The results indicate that when the gas atomization pressure is 5.5MPa and the temperature is 1550°C the median diameter of the powder, which appears rough surface and low sphericity, is 54.38μm. When the gas atomization temperature is 1550°C, with the gas atomization pressure increasing from 5.5 to 6.5MPa, the powder size decreases from 54.38 to 35.51μm whereas the satellite ball of the surface increases. When the gas atomization pressure is 5.5MPa, with the gas atomization temperature increasing from 1550 to 1650°C, the powder size decreases from 54.38 to 36.63μm but the powders possess smooth surface and high sphericity. The phase structure of the powder is single α-Fe phase, and the solidification structure in the powder is mainly equiaxed grain along with a small amount of dendrite