Electromagnetic Characteristics and Microwave Absorbing Properties of a Novel Stainless Steel Powder

Abstract

In order to solve the problem of insufficient oxidation resistance and corrosion resistance of magnetic metal absorbent represented by carbonyl iron powder, a wave absorbing composite material which consists of different filling mass proportions of the atomized electrolytic stainless steel powder and paraffin wax is investigated. The electromagnetic (EM) characteristics and absorbing performance of the proposed composite material were tested with Agilent N5234A vector network analyzer in a frequency range of 2–18$$GHz. The experimental results show that the real and imaginary parts of the dielectric permittivity of stainless steel powder/paraffin composites will increase with the filling mass fraction in the test frequency band, while the real part of the permeability ${\mu }^{\prime }$ decreases with the increase of the mass fraction, and the imaginary part ${\mu }^{\prime \prime }$ increases with the increase of the mass fraction. At a thickness of 3$$mm, with the filling mass fraction increasing from 20$$wt.% to 60$$wt.%, the peak frequency of reflection loss (RL) moves to low frequency from 17.92$$GHz to 16$$GHz. Meanwhile, the minimum reflection loss (RL${}_{\mathrm{\text{min}}}$) also shows a downward trend, and the RL${}_{\mathrm{\text{min}}}$ value with a filling mass fraction of 60$$wt.% is −8.93$$dB. It can be seen that stainless steel powder shows good microwave absorbing performance, and it has excellent anti-oxidation, and anti-corrosion properties. Based on the excellent performance of stainless steel powder, its absorption performance is expected to be further improved through multi-layer optimization design, so as to meet the needs of electromagnetic protection in harsh environments.