采用真空悬浮熔炼和高能球磨工艺制备了Al8 Mn5合金粉体,使用 SEM、XRD 和网络矢量分析仪研究高能球磨对Al8 Mn5合金粉体微波吸收特性的影响。结果表明,随着球磨时间的增加,粉体的颗粒及晶粒变细,粉体吸收峰频率向低频移动;样品厚度为1.5 mm时,未经球磨的粉体在13-18 GHz频段内有3个吸收率〉90%的吸收峰,呈现出较好的频宽效果;经24 h 球磨后粉体在13.2 GHz 频率处有最大吸收峰,其反射率最小值约为-37.5 dB (吸收率为99.98%);Al8 Mn5粉体对电磁波的吸波机理与吸波涂层内的电磁损耗和涂层厚度对电磁波的干涉损耗影响有关。
Al8 Mn5 alloy powder was prepared by vacuum levitation melting and high-energy ball milling,effect of high-energy ball milling on microwave absorbing properties of Al8 Mn5 alloy powder were investigated with the help of scanning electron microscope (SEM),X-ray diffraction (XRD)and network vector analyzer.The results show that:with the increase of milling time,powder particles and grain becomes finer as powder absorption peak frequency move to the low-frequency;when the sample thickness was 1 .5 mm,without ball milling pow-der has three absorption rate more than 90% of absorption peak in the range of 13-18 GHz,showing a good fre-quency width effect;the 24 h ball milled powder has the maximum absorption peak in the 13.2 GHz frequency, the reflectivity minimum -37.5 dB (absorption rate 99.98%);the absorbing mechanism of Al8Mn5 powder on the electromagnetic wave related to electromagnetic loss within the absorbing coatings and effect of coating thickness on the interference loss of electromagnetic wave.