Si掺杂对NdFeB磁粉吸波性能的影响

Effect of Si substitution on microwave absorbing properties of NdFeB magnetic powders

采用熔炼–高能球磨–微氧化–晶化热处理的工艺,按照质量比ζ(Nd:Fe:Si:B)=8.24:(86.64–x):x:4.12(x=0,1,3,7)制备了NdFeSiB磁粉,借助X射线衍射仪和网络矢量分析仪等,研究了磁粉中Si含量对其相组成和吸波性能的影响。结果发现:当x=0和x=1时,所制粉体的组成相为α-Fe和Nd2O3相;x=3时,其粉体的组成相为α-Fe、Nd2O3和FeSi3相;x=7时,其粉体的组成相为α-Fe、Nd2O3、FeSi3和NdFeSi相。当涂层厚度为1.5 mm时,随Si含量的增加,所制粉体的反射率逐渐减小,吸波带宽逐渐增大,吸收峰先向低频移动然后向高频移动。

According to the mass ratio （（Nd：Fe：Si：B） = 8.24：（86.64-x）：x：4.12 （x = 0, 1, 3, 7）, NdFeSiB magnetic powders were prepared by smelting-high energy ball milling-micro-oxidation-recrystallization techniques. The effects of Si content on phase compositions and microwave absorbing properties of the prepared powders were investigated by X-ray diffraction and vector network analyzer. The results show that the prepared powders are consist of a-Fe and Nd2O3 phases when x = 0 or x = 1; the prepared powders are consist of a-Fe, Nd2O3 and FeSi3 phases when x = 3 and the prepared powders are consist of a-Fe, Nd2O3, FeSi3 and NdFeSi phases when x = 7. With the increasing of Si content, the wave reflectivity of the prepared powders decreases, the absorption bandwidth broadens and the absorption peak moves to lower frequency first and then moves to higher frequency gradually when the coating thickness is J.5 mm.