扁平化对FeSi吸波材料微波电磁性能的影响

为阐明吸收剂颗粒形状与吸波材料微波电磁性能之间的关系,采用机械球磨工艺对气雾化球形FeSi合金粉末进行扁平化处理并制成FeSi吸波材料。借助SEM和矢量网络分析仪,研究了球磨时间对FeSi颗粒形貌及1～18GHz内吸波材料电磁参数与吸波性能的影响。结果表明:随着球磨时间的增加,FeSi颗粒的扁平率增大。与未球磨样品相比,球磨32h的FeSi合金吸波材料的ε'在整个频率范围内增大了0.5倍,μ'(在1GHz时)由1.24增大到1.94,μ"(在1GHz时)由1.00增大到1.30。扁平化处理明显改善了FeSi吸波材料的低频吸波性。

Effect of flattening on the microwave electromagnetic properties of FeSi microwave absorbing materials

To fully understand the relationship between the particle shape of absorbents and the microwave electromagnetic properties of microwave absorbing materials, gas atomized spherical FeSi alloy powders were flattened by mechanical ball-milling and then made into FeSi microwave absorbing materials. The effects of milling time on the particle shape of FeSi powders and on the electromagnetic properties as well as microwave absorption properties of the microwave absorbing materials in the range of 1～18 GHz were studied by scanning electron microscope and vector network analyzer. The results show that the aspect ratio of FeSi powders increases with increasing milling time. Compared with control samples (without milling), the ε' of the microwave absorbing materials milled for 32 h increases by 0.5-fold within the frequency range studied, while their μ' increases from 1.24 to 1.94 and μ" increases from 1.00 to 1.30 at 1 GHz. Flattening significantly improves the microwave absorption property of the microwave absorbing materials at low frequency.