Multifunctional interstitial-carbon-doped FeCoNiCu high entropy alloys with excellent electromagnetic-wave absorption performance

Abstract

Electromagnetic-wave absorbing (EMA) materials that have efficient absorption performances, great mechanical properties and chemical stability are rare and yet essential for communication security and protection. Herein, flaky interstitial-carbon-doped FeCoNiCu high entropy alloys (HEAs) as novel EMA materials were successfully prepared by high-energy ball-milling method. Interstitial-carbon doping as a modulating approach impacted the phase forming, morphology and electromagnetic properties of FeCoNiCu HEAs. Impedance matching was significantly optimized via tuning interstitial carbon contents. The carbon-doped FeCoNiCu HEAs with appropriate carbon contents delivered superior EMA performance compared with other HEAs EMA materials. Strong reflection loss as low as -61.1 dB in the Ku band, broad effective absorption bandwidth of 5.1 GHz was achieved for FeCoNiCuC0.04. Moreover, the carbon-doped FeCoNiCu HEAs exhibited excellent mechanical hardness and chemical stability. This work not only suggests that interstitial-carbon doping is an available approach to tuning electromagnetic properties of HEAs, but also presents carbon-doped FeCoNiCu HEAs as promising EMA materials for civilian and military due to the efficient absorption, broad bandwidth, great durability and stability.