Electromagnetic Properties Of FeSi Alloy Powder Preparation By Centrifugal Atomization

Centrifugal atomization by the rotating disk process is usually used to mass-produce alloy powder, it is an efficient and low cost technology for producing high quality powder with narrow size distributions, however, spherical shape is the common morphology for the powder which is produced by centrifugal atomization method. But as the electromagnetic wave absorption absorbent, larger length-diameter ratio can increase the absorption properties. This paper devises a centrifugal atomization equipment and elliptic/spherical shape Fe90Si10, Fe80Si20 and Fe70Si30 alloy powders were produced. The prepared powders were characterized by XRD, SEM and vector network analysis etc.Single phaseα-Fe, Fe1.34Si0.66 and FeSi are formed Fe90Si10, Fe80Si20 and Fe70Si30, respectively. And the values of the real part of complex permittivity increase gradually and then decrease with increasing weight percentage of Si, the values almost constant over the whole measured frequency of the imaginary part complex permittivity (～0.2). The complex permeability for the Fe90Si10 is much higher than Fe80Si20 and Fe70Si30.The values of the real part of complex permittivity and imaginary part permeability increasing with the filling ratios of alloy powder. The Fe90Si10 possess the broader frequencies and stronger microwave absorption properties than Fe80Si20 and Fe70Si30 with the sample thicknesses are 2mm,3mm and 4mm, respectively. In addition, a larger filling ratio, can obtain better absorption performance.Compared with commercial Fe91Si9, the Fe90Si10 not only has better electromagnetic properties but also owns better microwave absorption properties performance. Carbonyl iron uniformly mixes with commercial Fe91Si9, Fe91.2Si3.1P2.9Sb2.8 and prepared Fe90Si10, respectively. According to a given proportion, the prepared composites powder has excellent microwave absorbing properties. As carbonyl iron and FeSi powder is weighed by ratio of 1:1, the best absorption properties can be acquired. A better electromagnetic impedance match could be established due to the efficient combination of the carbonyl iron and FeSi in the composites powder, resulting in the enhanced microwave absorption.