机械合金化时间对FeSiAlCr合金微粉电磁特性的影响

The Effect of Mechanical Alloying Time on Microstructure and Electromagnetic Properties of Flaky FeSiAlCr Powders

以分析纯Fe、Si、Al、Cr粉为原料,采用机械合金化法制备FeSiAlCr合金微粉。利用X射线衍射仪、扫描电镜和微波矢量网络分析仪分别研究了球磨后微粉的形貌、相结构及电磁参数,计算了微粉的微波反射率。结果表明:采用机械合金化方法,球磨时间为80 h时制备得到的FeSiAlCr合金微粉呈细片状,颗粒尺寸约为3um左右;随着球磨时间的延长,Si和Al的衍射峰逐步消失,而Cr原子与Fe原子发生置换固溶反应;FeSiAlCr合金微粉在厚度为2 mm,频率为6～10GHz范围内具有较低的反射率,且在7.9GHz处反射率最小值达到为-25.08 dB。

FeSiAlCr powders were prepared by mechanical alloying（MA） with analytical-purity Fe,Si,Al and Cr powders.The morphology and microstructure of as-milled powders were investigated by SEM and XRD respectively.Electromagnetic parameters were measured with a microwave vector network analyzer,and reflectivities of the powders were calculated.The results showed that the powders were flaky,and the size was about 3um after 80h milling by MA.The diffraction peaks of Si and Al were disappeared with the increasing milling time.Solid solution reaction appended between Cr and Fe atoms.In the frequency range from 6 to 10 GHz,the reflectivity was low when the thickness was 2mm,and the minimum reflectivity was-25.08dB at 7.9GHz.