Preparation Of FeSiN Alloy Powder And Its Soft Magnetic Properties And Electromagnetic Properties

The highest M_s value of iron nitride material is the??-Fe₁₆N₂ electronic compound,and the Re-Fe-N alloy powder is a new-generation permanent magnetic material.To study these two types of materials,we must first solve the problem of the preparation of FeSiN powder.However,at present,the preparation of FeSiN powder is difficult,the technology is complex,and it is difficult to apply to industrialize production and practical application.Therefore,it's of practical significance to explore a new simple and effective preparation method.In this project,firstly,the FeSi amorphous powders were prepared by master alloy melting,vibration crushing,and screening,which called the precursors of FeSiN powders.The precursors were first processed by high-temperature nitriding process to prepare FeSiN powders.It studied what effect do the factors such as nitridation time,nitriding temperature and nitriding FeSi content on the FeSiN powder properties.Finally,the application of FeSiN powder was studied in detail.This article successfully produce the flake-shaped FeSi powder which conforms to powder liquid nitriding.The shape of the flake FeSi powder was irregular and the thickness was about 10?m.A high-temperature nitriding process for preparing FeSiN powder was developed and the precursor was subjected to high-temperature nitrogen.After the treatment,single-phase?-Fe?Si?₃N powders were successfully prepared,and the optimal nitriding process conditions were optimized:the nitriding temperature was 550?C,the holding time was 1 h,and the mass ratio of the nitriding medium to the powder was 100:5.Studies show that this high-temperature nitriding technology has the advantages of convenience,speed,low cost and high efficiency;the prepared powder is in the form of flakes,and the N element is more evenly distributed in the FeSi phase.The powder has good soft magnetic properties and its saturation magnetization is as high as 139 emu/g.In the application of radar wave absorber,the precursor-platelet FeSi powder and FeSiN powder have excellent microwave absorption performance in the frequency range of 0.3 to 8.5 GHz.Nitriding time has a great influence on the complex permittivity and dielectric loss of FeSiN powders.The real part?'of the complex dielectric constant of the 2 h nitriding FeSiN powder is about 10²0 at 3.0⁸.5 GHz;the tan?e value is greater than 1.0 at 0.3⁵ GHz,and it is about 0.75^at 6⁸.5 GHz.0.8,which shows excellent dielectric loss;when tan?m increases in the frequency band of 0.3⁸.5 GHz,its value is greater than 1.0 in the frequency band of 4.2⁸.5GHz,with excellent magnetic loss characteristics.The loss mechanism is the combined mechanism of dielectric loss and magnetic loss.In the application of magnetic powder core,FeSiN magnetic powder core has good anti-DC bias characteristics.When the applied DC magnetic field is about 7000A/m,the magnetic permeability of FeSiN magnetic powder core decreases from 38 to29,and the decrease rate is only about 23%.