Study On Magnetic Properties And Magnetic Domain Structure Of Fe-Si-B Amorphous Alloys

Fe-based amorphous alloys have special atomic structure characteristics,so that some of their soft magnetic properties are obviously better than the traditional crystalline alloys.As a high performance soft magnetic material,Fe-based amorphous alloy is widely used in power electronics industry,which greatly improves the performance of magnetic products and makes magnetic products more miniaturized and energy-saving.However,the saturation magnetization(Bs)and glass forming ability of Fe-based amorphous alloy limit the application in industrial production,and the demand for high-performance materials in the high-precision field is very urgent.Therefore,it is of great practical significance to improve the saturation magnetization and other properties of Fe-based amorphous alloys.In this paper,the composition,magnetism and domain structure of Fe-based amorphous alloys with high saturation magnetization are studied.The Fe-based amorphous alloys are prepared by high vacuum arc melting and melt-spinning method.The magnetic properties of amorphous alloy ribbon are tested by MATS magnetic measuring device.The differential scanning calorimeter(DSC)is used to study the crystallization kinetics.Kissinger and Ozawa models are used to fit and analyze the data,so as to obtain the activation energy of crystallization,and then study the difficulty degree of material crystallization.Mumax software is used to conduct micromagnetic simulation on the Fe82Si3B15 amorphous alloy,and the internal magnetic moment distribution,magnetism and energy changes of the amorphous alloy are studied at different frequencies or temperatures.The main results of the study are as follows:(1)When the Si/B is 3/17,the Bs of the amorphous alloy reaches 1.603 T.When the atomic percentage of Fe is kept at 82%,and when the atomic percentage of Si is 3%,the Bs of the amorphous alloy is the highest,reaching 1.654 T,so the component with the best magnetic properties is Fe82Si3B15.Fine tuning of the composition range shows that the best composition range is 2.5%?3.5%Si atom percentage when Fe atom percentage is 82%.Within this composition range,the Bs of the Fe-based amorphous alloy exceeds 1.638 T.(2)Under the constant working magnetic induction intensity(0.02 T?0.1 T),the magnetic field frequency is within the frequency range of 30 KHz?100 KHz.As the magnetic field frequency increases,both elastic permeability and viscous permeability decrease and the magnetic loss increases.At a constant magnetic field frequency(30KHz?100 KHz),coercivity increases linearly with the increase of working magnetic induction intensity,and magnetic loss increases in the form of power function.(3)The crystallization activation energy of Fe82Si3B15 amorphous alloy is lower than that of Fe79.5Si9.5B11 amorphous alloy,while the melting point of Fe82Si3B15 amorphous alloy is about 7? higher than that of Fe79.5Si9.5B11 amorphous alloy.Through production field tests,Fe82Si3B15 amorphous alloy has excellent glass forming ability and thermal stability,and has high Bs and other excellent magnetic properties.(4)Domain structure simulation shows that zeeman energy increases rapidly with the increase of frequency in the initial magnetization phase of Fe82Si3B15 amorphous alloy.With the increase of magnetic field frequency,the time needed to form the same magnetic domain structure is shortened,and the internal magnetic moment turns to the magnetic field direction more quickly.In the initial magnetization phase,double-C domain structure only exists at 10 MHz,while maze domain structure appears at 500 MHz and 1GHz,and flower domain structure appears in all three frequencies.The flower region decreases with increasing frequency of magnetic field.In the remanent phase,flower domain structure appears at both 500 MHz and 1 GHz,and the flower region continues to expand internally with the magnetization,while double-C domain structure appears at 10 MHz.In the coercive stage,double C magnetic domain appears,and the precession of magnetic moments at 500 MHz and 1 GHz is more complicated than that at 10 MHz.Moreover,at 1 GHz,the magnetization process is accelerated,and the time to reach the remanent magnetic field and coercive point is shortened.With the increase of temperature,the internal magnetic moment is deflected by the temperature field and deviates from the direction of the external magnetic field.