Effect Of Superheat And Cryogenic Treatment On The Properties Of Fe-based Amorphous Bands

Fe-Si-B series alloys have been widely used as functional material in magnetic field due to their low coercivity,high magnetic permeability,good processing performance and low cost.Silicon steel sheet with grade 1K101 which is used in the transformer core has been gradually replaced by Fe78Si9B13 amorphous bands.In the preparation process of Fe78Si9B13 amorphous bands,the magnetic properties of the materials are unstable with the change of the process parameters.In this research,In order to find the corresponding relationship between superheat and annealing temperature and provide reference for industrial,the effects of superheat and annealing temperature on the magnetic properties and stability of Fe78Si9B13 were studied.In addition,cryogenic treatment is an important heat treatment process to improve the strength,toughness and wear resistance of the material.However,there are few studies on the effect of cryogenic treatment on amorphous alloys.The effects of cryogenic treatment on the properties of amorphous alloys were studied,which has certain significance to broaden the application fields of amorphous alloys.The Fe78Si9B13 amorphous bands were prepared by single roll quench method,the samples were annealed and treated by cryogenic treatment.The magnetic properties of the alloy were measured by silicon steel tester and VSM.The main experimental results are as following:The XRD results show that Fe78Si9B13 amorphous alloy prepared under three superheat and the samples treated with cryogenic treatment for 12 h,24h,48 h and 96 h are all completely amorphous.The increase of superheating temperature and the extension of cryogenic time are all beneficial to improve the width of the supercooled liquid region of the amorphous alloy,and can all improve the thermal stability of Fe78Si9B13 amorphous alloy.With the increase of superheat,the glass transition temperature Tg,crystallization initiation temperature Tx,peak temperatures of first and second crystallization peaks Tp1,2 as well as the crystallization enthalpy ?H obtained by integrating the area of two peaks all show a downward trend.Moreover,the increase of superheat of the amorphous bands lead to both the stability and saturation flux density decrease while both the coercivity and remanence increase.When the annealing temperature increased properly,good performance can be obtained.With the extension of cryogenic time,both saturation magnetic induction intensity and crystallization peak area of Fe78Si9B13 amorphous alloy increases while crystallization volume fraction decreases,and the Bs obtained is between quenching and annealing at 633 K to 653 K,Tg,Tx,?Tx,Tp1,2 were changed,and?Tx is higher than the quenched sample.After cryogenic treatment,the sample does not break when it is folded 180°.Moreover,the toughness increases with cryogenic treatment.As the time of cryogenic treatment prolongs,the ductility increases.