Study On Glass Formation,Oxidation Resistance And Corrosion Resistance Of Fe-based Amorphous Alloy

Amorphous alloys have a unique structure compared to crystals,and do not have crystal defects or segregation of components,and are generally considered to exhibit excellent corrosion resistance and oxidation resistance.However,the actual production of thin strips has a large number of defects on its surface,and the surface imperfections make it easy for amorphous strips to oxidize and corrode from the se defect locations.Corrosion often occurs in practical applications.Oxidation of the heat treatment will distort the soft magnetic properties of iron-based amorphous/nanocrystalline and affect the performance.In this paper,a series of Fe-based amorphous alloy thin strips were prepared by adding a small amount of Nb,Mo,Cr,Ti,Y,Mn,Al,and Ni elements,and micro-alloying Fe-Si-B-Cu-Nb was studied.With the Fe-Si-BP-Cu-?C,Hf?alloy amorphous alloy formation,soft magnetic properties,anti-oxidation and corrosion resistance.?1?In Fe_74.5Si_13.5B₉Cu₁Nb₁M₁?M:Fe,Ni,Mn,Mo,Cr,Ti,Y,Al?alloys,in addition to the obvious?-Fe crystallization occurring when M is Al,Ni,Mn,The addition of Mo,Cr,Ti,and Y all forms a completely amorphous state.Except that M is a Y element,the remaining thin strips of the sample are folded continuously and have good bending plasticity.In addition to Ni,micro-alloying increases the crystallization initiation temperatures T_x1 and T_x2.When M is Ni,Mo,Ti,and Y,it increases the thermal stability interval of?-Fe.The temperature?T_c?decreases.?2?After microalloying,the saturation magnetization Ms of the quenched Fe74.5Si13.5B9Cu1Nb1M1?M:Ni,Mn,Mo,Cr,Ti,Y?alloy decreases,and the range of change is within the 148 emu-167 emu/g range.Coercivity Hc and M increased from12 A/m to 20.6 A/m when the initial component was Ni,and the addition of other elements decreased slightly.?3?According to the thermogravimetric curve under dry air,the addition of Cr element will seriously reduce the anti-oxidation ability.The best effect of the addition of Mo element to the anti-oxidation effect is:Mo>Ti>Mn>Y>Ni>Fe>Cr.773 K isothermal annealing,air oxidation and vacuum,the saturation magnetization decreased significantly,the coercive force increased,the sample oxida tion occurred to reduce the soft magnetic properties.Electrochemical tests show that the corrosion potential decreases with the increase of Mn and Ni,while the corrosion potential increases negatively.After the addition of Y,Mo,Ti,and Cr elements,th e corrosion current decreases and the corrosion potential moves in the positive direction.Improve the corrosion resistance of the alloy.?4?For(Fe₈₅Si_1.4B₉P₄Cu_0.5C_0.1)_100-x00-x M_x?x=0.1,0.2,0.3;M=Mo,Cr,Ti,Nb,Y,Mn,Al,Ni?alloys,only x=0.1 at%and M=Y,completely amorphous was formed.In all other cases,there was a clear crystallization of?-Fe.Alloys of(Fe₈₅Si_1.4B₉P₄Cu_0.5C_0.1)_100-xY_x?x=0,0.05,0.1,0.15?and(Fe_84.2Si₂B₉P₄Cu_0.5C_0.3)_100-x00-x Y_x?x=0,0.1?alloys with varying Y contents were formed.Completely amorphous,there are three distinct exothermic peaks in the DSC curve under dry air,corresponding to the precipitation of?-Fe phase,precipitation of boride and occurrence of body oxidation.The(Fe₈₅Si_1.4B₉P₄Cu_0.5C_0.1)_100-x00-x Y_x?x=0,0.05,0.1,0.15?alloy increases slightly with Y,and the crystallization starting temperatures T _x1 and T_x2 do not change significantly.?5?ThesaturationmagnetizationM_softheas-quenched(Fe₈₅Si_1.4B₉P₄Cu_0.5C_0.1)_100-xY_x?x=0,0.05,0.1,0.15?amorphous alloy decreases with the increase of Y from 170 emu/g to 161.1 emu/g,coercive force Hc is 10.3 A/m,6.7A/m,9 A/m,9.2 A/m;(Fe_84.2Si₂B₉P₄Cu_0.5C_0.3)_100-x00-x Y_x?x=0,0.1?amorphous alloy Ms and H_c were 172 emu/g,11.2 A/m,166.8 emu/g,and 8.3 A/m,respectively.The thin strip sample was folded in half,the crease was observed by SEM,and it had good bending plasticity.?6?Thethermogravimetriccurvesofamorphousalloys(Fe₈₅Si_1.4B₉P₄Cu_0.5C_0.1)_100-xY_x?x=0,0.05,0.1,0.15?under dry air show that the addition of Y element significantly improves the oxidation resistance of amorphous alloys.The XRD patterns of x=0 and x=0.1 samples after heat treatment in air under the same conditions were compared.When 705K,x=0 was higher than x=0.1,indicating that Fe₂O₃ oxide peaks appeared first,indicating that the addition of Y added some inhibition of iron oxidation.The air and vacuum conditions are 705K isothermally annealed.Compared with vacuum,the air saturation increases significantly due to the air oxidation and the coercive force increases.The oxidation of the sample reduces the soft magnetic properties.A slight addition of Y can reduce the adverse effects of oxidation on the soft magnetic properties.Electrochemical tests showed that the corrosion potential of the sample after a slight addition of Y was increased negatively,and there was a slight sign of passivation,the corrosion current decreased,and the corrosion resistance of the alloy was improved.?7?(Fe₈₆B₁₂P_0.5Si_0.5Cu_0.5Hf_0.6)_99.9M_0.1?M:Fe,Ni,Mn,Nb,Y?Alloys 0.1at%of Ni,Mn,Nb,and Y are formed after the addition of four elements.In the amorphous state,three distinct exothermic peaks appear in the dry air DSC curve.The initial crystallization temperatures T_x1 and T_x2 did not change significantly,and the body oxidation start temperature T_b decreased slightly.Micro-alloying can improve the oxidation resistance and corrosion resistance of the alloy.