片状FeSi合金的制备及其低频吸波性能研究

摘要

In order to improve FeSi alloy permeability in low frequency and improve its low frequency microwave absorbing properties,the authors fabricate flaky shape FeSi alloy with fine microwave absorbing properties in low frequency by using high-energy ball milling to achieve mechanical shape change.They also study the influence of milling time on the alloy's morphology,structure,impedance matching and low frequency electromagnetic properties.The results show that the spherical particles may be deformed into a sheet after 4h ball milling,and that the deformation rate of FeSi alloy increases with ball milling time.In terms of electromagnetic performance,with ball milling time increase,low frequency permeability (2~8 GHz)of FeSi alloy increases significantly,permittivity increases significantly in whole frequency range,obtaining good low frequency impedance matching properties,and the decay properties of microwave significantly improves.The FeSi alloy with the ball milling time of 8h at 300 r/min has the best flaky shape and excellent microwave absorption properties in low frequency,with the minimum reflectivity reaching to -13 dB at 2.4 GHz.%为提升 FeSi合金低频磁导率，改善其低频吸波性能，通过高能球磨法对 FeSi 合金进行力学改形，制备出低频性能良好的片状 FeSi合金，并研究了球磨时间对其微观形貌、结构、阻抗匹配和低频电磁性能的影响.结果表明：在球磨4 h以上时可以将球形颗粒变形为片状，且片状 FeSi 合金的宽厚比随着球磨时间增加而逐渐增大；在电磁性能方面，随球磨时间增加片状 FeSi合金磁导率在低频段2~8 GHz 得到明显提高，介电常数在全频段均显著提高，低频段阻抗匹配性能得到改善，电磁波损耗能力大幅提升.采用300 r/min球磨8 h的片状 FeSi 合金具有最佳的低频吸收效果，在2.4 GHz处反射率达到-13 dB.