Enhanced microwave absorption performance of FeSiBCCr flake amorphous powder from ball milling.

Magnetic loss electromagnetic wave absorber materials have always been a research hotspot in the electromagnetic wave absorption field due to their excellent magnetic loss performance. However, their use is limited by the problem of impedance mismatch. In this study, taking into account the good soft magnetic properties and high amorphous forming ability of the FeSiBCCr amorphous alloy system, the spherical powder was transformed into a flaky powder through high-energy ball milling and uniformly mixed with a certain mass ratio of paraffin to produce high performance wave absorber. It was found that, compared with spherical powders, the flaky powder particles mixed with paraffin not only enlarged the surface area of the filler and improved the mechanism of polarization, but also increased the complex permeability and complex permittivity, thus providing strong electromagnetic wave attenuation capability. The flaky amorphous powder after ball milling for 4 h shows the highest electromagnetic wave absorption performance, and the minimum reflectivity loss at the frequency of 9.25 GHz reaches − 40.82 dB when the thickness of the wave absorber (50 vol% powder) is 2.5 mm. The maximum effective absorption bandwidth is up to 4.9 GHz. The FeSiBCCr flaky amorphous powder prepared in this work shows a broad absorption potential above 18 GHz, which can well solve the impedance mismatch problem, and provides a strategy for the synthesis of magnetic loss electromagnetic wave-absorbing materials with impedance matching and broad absorption strength. [ABSTRACT FROM AUTHOR]