试件厚度对铜渣-水泥基复合材料吸波性能的影响

铜渣为炼铜的工业副产品,将30%体积掺量的铜渣代替砂子,制备不同厚度的铜渣-水泥基复合材料试件,在2~18 GHz微波频段内,采用弓形反射法测试其微波反射率,同时测试其力学性能,并用扫描电子显微镜(SEM)分析其微观结构。结果表明:在2~18 GHz微波频率范围内,随着材料厚度的增加,微波反射率逐渐增加,当厚度为10 mm时,最小反射率为-22.17 d B,低于-10 d B吸收峰的累积有效带宽(吸波材料的工作频带宽度越大越好)为2.6 GHz。掺加铜渣后,水泥正常水化,复合材料力学性能无明显降低。铜渣可应用于具有吸收微波功能要求的水泥结构物。

Effects of Thickness on Absorbing Properties of Cement-based Composites with Copper Slag

Copper slag is byproduct of copper smelting industry.In this work,specimens of cement-based composites with different thicknesses were prepared,in which 30％ volume natural sand was replaced by copper slag.Reflectivity of samples was tested by naval research laboratory (NRL) testing system in the frequency ranges of 2～ 18 GHz.Mechanical properties were also tested and scanning electron microscopy (SEM) was adopted to observe microstructures of the samples.The results show that microwave reflectivity increases with the increase of thickness of the composites in the microwave frequency range of 2 ～ 18 GHz.When the thickness is 1 0 mm,the minimum reflectivity can reach-22.17 dB.Meanwhile,lower-10 dB effective bandwidth of absorption peak is 2.6 GHz.After addition of copper slag,cement can hydrate as normal and mechanical properties of the composites do not decrease significantly.Copper slag can be widely used in cement structures with requests of microwave absorption function.