Dy和Al对Fe-Co合金微波吸收性能的影响

采用高真空电弧熔炼和高能球磨相结合的方法制备 Dy-Fe-Co 和 Dy-Fe-Co-Al合金微粉,利用X射线衍射技术（XRD）、扫描电镜分析方法（SEM）和矢量网络分析仪对合金粉的相结构、颗粒形貌和吸波性能进行分析。研究发现：随着Dy的添加,DyxFe90-xCo10(x=6, 9, 12)合金的吸收峰从低频向高频移动;在低频端,Dy6Fe84Co10合金的微波吸收性能优于其他合金,在d=1.8 mm厚度下,其吸收峰出现在3.6 GHz处,峰值达到 –6.7 dB;Al的适当添加可有效改善Fe-Co合金在低频端的微波吸收性能。在d=1.8 mm厚度下,Dy12Fe70Co10Al8合金的吸收峰在5.4 GHz处,峰值达到 –9.2 dB,在3~6 GHz频率范围内其微波吸收性能优于Dy12Fe78Co10合金     

基于超材料设计实现C/Co复合材料的超宽带吸收

本文通过简单的一步热解法合成了C/Co复合材料,在材料质量填充浓度为35%时观察到其具有优异的介电频散性能。当材料厚度2.5 mm时,该复合材料在11.2 GHz的最小反射率为-23.7 dB,小于-10 dB的带宽为3.8 GHz。为了进一步提高吸收体的吸波性能,我们利用全介质超材料的设计对吸收体的宏观结构进行优化,此方法成功地将小于-10 dB的吸收带宽扩展到15 GHz （7.0~22.0 GHz）。该研究结果可以为高性能微波吸收材料的制备工艺和结构设计提供有价值的参考。     

热处理对TbFeCr合金微波吸收性能的影响

采用电弧熔炼与高能球磨相结合的方法制备Tb9Fe88Cr3合金粉体,利用XRD、SEM和矢量网络分析仪分析粉体的微结构及微波吸收性能。研究发现进行微氧化处理的合金微粉在低频端吸波性能优于未处理的合金微粉。在微氧化处理基础上,进一步研究热处理温度对合金微波吸收性能影响,研究发现:当热处理温度在350℃时,吸收峰在7GHz处,其峰值达到–11.5dB,随着真空热处理温度升高,合金微粉吸收峰向低频移动,反射率增大;当热处理温度为450和550℃时,吸收峰频率与仅做微氧化处理合金的吸收频率相近,吸收峰值减小了2~3dB,低频端吸波性能得到进一步改善。     

球磨工艺对Y-Fe-Cr合金吸波性能影响

采用XRD、SEM和矢量网络分析仪分析相结合的方法研究球磨时间对Y-Fe-Cr合金微粉吸波性能的影响.结果表明:随着球磨时间从50 h不断增加,Y9Fe88Cr3吸波合金的吸收峰逐渐向低频移动;当球磨时间低于70 h时,合金扁平化及各向异性较好,其反射率较低,合金粉末吸波性能较好,在吸波涂层厚度为d=1.8 mm条件下,球磨时间为50 h和70 h的合金粉末的电磁波吸收峰峰值分别达到-14.7 dB和-14.4 dB,＜-10 dB的吸波带宽均达到7 GHz;当球磨时间达到80 h后,由于合金粉末颗粒碎化变细导致各向异性变差,其吸波性能变差,在吸波涂层厚度为d=1.8 mm条件下,合金粉末电磁波吸收峰峰值和＜-10 dB的吸波带宽分别为-12.5 dB和3.5 GHz,较球磨时间为70 h之前的合金粉末的吸波峰值和带宽减小了2 dB和3.5 GHz.研究结果为制备同类吸波合金微粉提供一定的理论依据.     

Research on microwave electromagnetic properties of Tb-Fe-Cr alloy

The Tb-Fe-Cr alloy powders were prepared by the arc melting method and high energy ball milling.The phase structure and themicrostructure of the alloys powders were analyzed by X-ray diffraction(XRD) and scanning electron microscopy(SEM),and then their microwave absorbing properties were analyzed by Vector network analyzer.The results showed that the absorption peak values of Tb9Fe88Cr3alloy with a material thickness of 2.0 mm were lower than-16.5 dB when ball milling time was from 50 to 60 h,and the wide frequency ofreflectivity under-10 dB were all more than 4 GHz.When the ball milling time was 50 h,the alloy powders had better electromagnetic properties.The absorption peak value of alloy reached-25.8 dB,and the wide frequency of reflectivity under-10 dB reached 4.8 GHz.When theball milling time was more than 70 h,the alloy powders would become thinner,leading to worse electromagnetic properties of the alloy,theabsorption peak shifted towards low frequency under the same material thickness.The TbxFe97-xCr3(x=7,9,11,13,15 mol.%) alloy dealtwith 60 h ball milling time had better wide-frequency characteristic under 1.8 mm of material thickness.The absorption peak shifted towardshigher frequency region from lower frequency region with increased atom percent of Tb in the alloy,and the inflexion point appeared whenx=13.At low frequency,the microwave absorbing properties of Tb11Fe86Cr3 alloy was better than those of the others.The absorption peakvalue of Tb15Fe82Cr3 alloy was-24 dB,and the wide frequency of reflectivity under-10 dB was 4.5 GHz.