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

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.