FeCoNiMnAl high-entropy alloy: Improving electromagnetic wave absorption properties

摘要

We used mechanical alloying to prepare FeCoNiMn_(0.5)Al_x(x=0.0,0.1,0.2,0.3,0.4) alloy powders and then annealed at 773 K. All samples show a good soft magnetic performance. The maximum saturation magnetization (Ms) is 98.41 emu/g. With the increase of Al addition, the real part of the complex permittivity (ε') first increases and then decreases. The real part (μ') of the complex permeability varies between 1.76 and 2.1, and the imaginary part (μ'') varies between 0.53 and 0.74. The maximum reflection loss (RL) is - 38.414 dB. After annealing, new phases (CoFe_2O_4 and Al_(86)Mn_(14)) appear, improving the values of Ms (Ms_(max)= 124.33 emu/g) and H_c (Hc_(max)= 181.22 Oe). After annealing, the particle sizes of the powders also increase. All of these make the permittivity and permeability of the sample increase. The RL_(min) of annealed samples increase to - 42.851 dB. The results are significant to the research of high-entropy alloy powder as electromagnetic wave absorbing material.