| Amorphous alloys have good magnetic permeability characteristics,low losses,and high resistivity due to their short-range ordered long-range disordered microstructure characteristics.As a result,they have been widely used in transformers.In recent years,they have replaced silicon steel transformers.There are important applications in hightech materials such as energy,information,and defense.Amorphous nanocrystalline alloy is a material that precipitates nano-sized grains on an amorphous substrate.Compared with amorphous alloys,nanocrystalline alloys have both the high magnetic permeability and low loss of Fe-based amorphous alloys and Co-based amorphous alloys.And is an inexpensive iron-based material.At present,the preparation of amorphous nanocrystalline alloys mainly includes amorphous crystallization,pulsed magnetic field heating,mechanical ball milling,and inert gas condensation.Fe78Si9B13 amorphous alloy strip was prepared by single-roll spin-quenching method.The amorphous alloy was heat-treated under different conditions,including annealing at furnace cooling or air cooling,and water cooling.Differential thermal analysis(DSC),Xray diffraction(XRD),and vibration samples were performed.Magnetometer(VSM),transmission electron microscope(TEM)and Mossbauer spectroscopy were used to analyze the microstructure and soft magnetic properties of the alloy after heat treatment,and the electromagnetic absorption performance of the amorphous alloy was measured by a vector network analysis(VNA)instrument.The results showed that the strip would undergo secondary crystallization,and the heat treatment conditions affected the size and density of the precipitated primary crystallization product nanocrystalline ?-Fe(Si)particles,and affected the soft magnetic properties of the material.In the case of 400?isothermal annealing,the absorption frequency of the material increased toward the high frequency when the holding time was increased;under air-cooled conditions,the absorption frequency of the material just started to move to the high frequency,and the temperature shifted to low frequency after the temperature further rises.By controlling the heat treatment conditions,the dynamic gegulate the absorption band of the material.In this paper,Fe78Si9B13 amorphous nanocrystalline alloy with excellent properties was obtained by controlling the heat treatment method.The absorbing performance in the high-frequency band was analyzed.It provided a new way to study the microstructure of amorphous alloys. |
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