Particle size and loading ratio dependent microwave absorption performance of FeSiAl alloy and the mechanism study

This paper investigates the microwave absorption performance of FeSiAl alloy powders with varying particle sizes and loadings. Potential mechanisms underlying the microwave absorption of the studied materials are discussed. The results reveal that FeSiAl material exhibits a relatively weak dielectric loss, while the dominant electromagnetic wave dissipation stems from its magnetic loss. Detailed study indicates that decreasing in average particle size and increasing in loading ratio of FeSiAl absorbent effectively modify the dissipative ability of the samples. As the average particle size increases, the natural resonance frequency of FeSiAl alloy powders shifts to lower frequencies. By optimization, it is found that FeSiAl alloy absorber sample with nominal 500 nm absorbent particle size and 80 wt% loading (500 nm-80wt%) achieved an effective absorption bandwidth (EAB) of 7.0 GHz (10.95–17.95 GHz) at1.83 mm matching thickness, while the 1 μm-75wt% sample at 1.96 mm matching thickness achieved the minimum reflection loss (RL_min) of −58.65 dB with an EAB of 6.1 GHz. Our results demonstrate that FeSiAl alloy powders are a novel, advanced high-performance absorbent with significant potential for a wide range of applications.