玻璃包覆铁基合金微丝的微结构与吸波性能

Microstruture and microwave absorbing ability of Fe-based glass-coated microwires

采用熔融纺丝工艺制备了玻璃包覆Fe基非晶合金微丝,通过X射线衍射分析研究了工艺条件对其微结构的影响,采用扫描电子显微镜分析了拉丝速度对微丝直径、玻璃包覆层厚度等结构参数和形貌的影响,利用微波矢量分析仪测量了2～18GHz的复磁导率和复介电常数,计算模拟了1mm厚度单层吸波材料的吸波性能。结果表明,通过冷却水急冷淬火可以获得非晶态结构,氩气保护可以防止合金氧化;拉丝速度提高有利于减小微丝直径,但玻璃包覆层的体积含量也随之增加;由该玻璃包覆Fe基非晶合金微丝设计的薄层吸波材料,在3～18GHz的宽频段内可以获得〈-2.5dB的微波吸收性能。

Amorphous Fe-based glass-coated microwires were prepared by the melt-spinning method.Effects of process conditions on microstructures of the microwires were analyzed by X-ray diffraction.Influences of drawing velocity on morphology and the structural parameters such as the microwire diameter and the glass-coated layer thickness were observed by scanning electron microscope.Complex permeability and permittivity of the microwires in 2-18GHz were measured by microwave vector network analyzer.Reflection coefficient of one-layer absorber with thickness of was numerically calculated.Results show that amorphous microstructure forms by water quenching.Oxidation of Fe-based alloy is avoided under Ar protection.The diameter of the microwire reduces and volume content of the glass-coated layer increases with higher drawing velocity.Absorbing ability of-2.5dB in the frequency range of 3-18GHz proves that these microwires may be used as microwave absorbers.