中文摘要：

采用非自耗真空电弧炉熔炼与高能球磨相结合的方法制备出Dy Ni2-xMnx（x=0.4,0.6,0.8,1.0）合金微粉,采用XRD、SEM和网络矢量分析仪等仪器对合金微粉的微观结构及其微波吸收性能进行研究。结果表明,与球磨前相比,Dy Ni1.2Mn0.8合金经50 h球磨后,其微波吸收性能得到显著改善,且球磨后其最小吸收峰频率向低频方向移动。Dy Ni2-xMnx（x=0.4,0.6,0.8,1.0）合金的最小反射率值随Mn含量的增加先减小后增大,吸收峰频率由高频向低频移动;其中Dy Ni1.2Mn0.8合金的吸波效果最好,当吸波涂层厚度为2.0 mm时,其最小吸收峰值在7.76 GHz处达到-20.6 d B,并系统地研究了Dy Ni1.2Mn0.8合金微粉的反射率随吸波涂层厚度的变化规律,发现随着吸波涂层厚度的增加,合金微粉的最小吸收峰频率逐渐向低频方向移动,Dy Ni1.2Mn0.8合金微粉的最佳匹配厚度为1.8 mm,此时其最小吸收峰值在7.92 GHz处达到-32.0 d B。

英文摘要：

The Dy Ni2- xMnx（ x = 0. 4,0. 6,0. 8,1. 0） alloy powders were obtained by arc smelting and high energy ball milling method. The structure and microwave absorbing properties of the alloy powders were studied by XRD,SEM and vector network analyzer,respectively. Compared with the powders not milled with high energy ball,the microwave absorbing properties of Dy Ni1. 2Mn0. 8alloy powders ball milled for 50 h are obviously improved. And the absorption peak frequency value shifts towards lower frequency region after high energy ball milling. At the same time, its minimum reflectivity value of Dy Ni2- xMnx（ x = 0. 4,0. 6,0. 8,1. 0） alloys decreases first and then increases,the absorption peak frequency value shifts towards lower frequency region with increasing Mn content in the alloys. Dy Ni1. 2Mn0. 8alloy shows the best absorbing properties,its minimum reflectivity value reaches- 20. 6 d B at 7. 76 GHz under 2 mm absorbing coating thickness condition. Moreover,the relationship between reflectivity and absorbing coating thickness of Dy Ni1. 2Mn0. 8alloy powders is systematically researched,the results find that the minimum absorption peak frequency value shifts towards lower frequency region with increasing microwave absorbing coating thickness. And the minimum absorption peak value of Dy Ni1. 2Mn0. 8alloy powders is- 32. 0d B at 7. 92 GHz with the best match condition d = 1. 8 mm.