Effect Of Fe-based Amorphous Structure Evolution On Ribbons Magnetic Propertise And Bending Ductility

With the increase consumption of energy,the researchers have developed a new material Fe-based amorphous alloy.As a new type of structure and function material,this alloy has excellent soft magnetic properties,mechanical properties and low price,widely used in motor,transformer,reactor,inductance coil,etc..However,the deficiency of the Fe-based amorphous is annealing embrittlement.Therefore,it is of great significance to study the influence of the composition and the annealing on the magnetic properties and ductile-brittle transition.In this paper,the magnetic properties and ductile-brittle transition of Fe₇₈Si₉B₁₃ and Fe₈₃C₁B₁₁Si₂P₃ alloy ribbons at different annealing time and annealing temperature are studied,and the best heat treatment condition for ribbon is obtained.Since the ductile-brittle transition of ribbons is relative to poisson's ratio,degree of mismatch and the bond between the atoms,which connect with the changing of Fe content,amorphous forming ability,thermal stability,crystallization activation energy,precipitated phase,magnetic properties and ductile-brittle transition of Fe_83-x(C₁B₁₁Si₂P₃)_?1+x/17??x=0,3,6,9 and 12?alloys system have been studied.Considering the Curie temperature Tc of Fe₈₃C₁B₁₁Si₂P₃ is much lower than that of Fe₇₈Si₉B₁₃ and the poisson's ratio of Ni element is higher than Fe element,in order to verify whether lower Curie temperature Tc is benefit for ribbon ductility,then(Fe_?1-x?N_ix)₇₈Si₄B₁₃P₅?x=0,0.2,0.4,0.6,0.8?alloys have been researched systematically,including the amorphous forming ability,thermal stability,magnetic properties and ductile-brittle transition.It is found that the coercivity of Fe₇₈Si₉B₁₃ ribbons can be improved in a short time at annealing temperature of 713 K or above,and the coercivity of Fe₈₃C₁B₁₁Si₂P₃ ribbons can be obviously reduced after at least 10 min at 633 K.Besides,for the Fe_83-x(C₁B₁₁Si₂P₃)_?1+x/17?with Fe content 83 at.%,the alloy ribbons have good bending ductility before and after the optimum annealing.However,when the Fe content of the alloy ribbons is 71 at.%,quenching ribbons show brittle characteristics.The transition temperature of bending ductility-brittleness decreases much faster than that of optimal soft magnetic properties with the increase of Fe content.In addition,with the increase of Fe content,the optimum annealing temperature moves to low temperature.The study of(Fe_?1-x?Ni_x)₇₈Si₄B₁₃P₅ confirms that the lower Curie temperature is not a major factor affecting the ductile-brittle transition of the ribbons.It is found that the ribbon is paramagnetic and the coercivity Hc is much greater,when the value of the variable x is 0.8.