Formation Ability And Soft Magnetic Properties Of Low Cost Fe-based Amorphous/nanocrystalline Alloys

Fe-based amorphous/nanocrystals have been intensively studied by researchers all over the world due to their excellent soft magnetic properties.For example,Fe-based amorphous/nanocrystals with the brand Finemet have been realized in industrial production and applied to peoples life.However,its saturation magnetization is not high,which is disadvantageous to the instrument lightweight and miniaturization.Also,the high cost further limits its development.In order to reduce the cost of raw materials and the difficulty of industrial production,we studied the Fe BCu amorphous/nanocrystalline alloy,so as to obtain a better amorphous formation ability,soft magnetic properties and lower cost.In this paper,the vacuum induction melting furnace,vacuum melt spinner,X-ray diffractometer（XRD）,high-temperature differential scanning calorimetry（DSC）,vibrating sample magnetometer（VSM）,and nano indentation instrument were used to prepare and study the Fe-based amorphous/nanocrystalline alloy.The main results are as follows:（1）The excellent soft magnetic properties of the quenched amorphous alloy without stress relief and crystallization annealing are important prerequisites for the excellent soft magnetic properties of the Fe-based amorphous/nanocrystalline alloy.fully amorphous Fe_（83.2-x）Co_xB₁₀C₆Cu_0.8（x=0,4,6,8,10 at.%）ribbons were prepared by replacing Fe element with Co element.The results show that Fe_77.2Co₆B₁₀C₆Cu_0.8has good amorphous formation ability and high thermal stability.The maximum saturation magnetization is 184.07 A·m²·kg^-1,and the coercivity is 13.55 A·m^-1.（2）In order to reduce the alloy cost,P element was used to replace the precious metal Co.Fe_78.8P_（14-x）B_xC₆Cu_1.2（x=0,7 at.%）amorphous/nanocrystalline alloys were prepared by isothermal annealing with small atom B element replacing Fe element.After annealing at 433℃and holding for 5 min,the saturated magnetization of Fe_78.8P₇B₇C₆Cu_1.2 is 154.63 A·m²·kg^-1,and the coercivity of Fe_78.8P₇B₇C₆Cu_1.2 is 3.22A·m^-1.The addition of B element can effectively restrain the brittleness of the alloy during annealing treatment.（3）In order to further reduce the cost and annealing brittleness,the Fe element was firstly introduced by the industrial pure iron,and the Si element with lower melting point was used to replace the C element.Secondly,the amorphous/nanocrystalline dual-phase structure was directly prepared by reducing the cooling rate.Fe_83.5Si_（8-x）B₈P_xCu_0.5（x=2,3,4,5at.%）amorphous/nanocrystalline alloys were prepared by changing the relative contents of Si and P.Among them,Fe_83.5Si₅B₈P₃Cu_0.5 has good amorphous forming ability,high thermal stability,saturation magnetization of 195.26A·m²·kg^-1 and coercivity of 24.86 A·m^-1.