Structure evolution and electromagnetic-wave absorption performances of multifunctional FeCoNiMnVx high entropy alloys with harsh-environment resistance

Magnetic high entropy alloys (HEAs) have great potential to be used as electromagnetic-wave (EMW) absorbers in harsh environments. The flaky FeCoNiMnVx HEAs were prepared by a novel, improved high-energy ball-milling method. The phase structure evolution, magnetic properties, corrosion resistance, oxidation resistance, and EMW absorption properties were investigated. The increase of V content had an abnormal effect on the phase-structure evolution. Due to the great magnetic-dielectric synergistic effects, the minimum reflection loss (RLmin) of annealed FeCoNiMnV0.5 at 7.5 GHz was 57.4 dB at a thickness of 2.24 mm, and the effective absorption bandwidth (EAB) reached 6.2 GHz (11.8–18.0 GHz).