Resaerch On Oxidation And Corrosion Behavior Of FeSiB(P/C) Amorphous Alloy

Fe based amorphous alloy as a new material alloy with good magnetic properties,mechanical properties and corrosion resistance attracts much more attention,due to their long-range disorder and short-range order miscrostructure.The FeSiB amorphous alloy ribbon occupies a dominant position in the domestic market.Although the Febased amorphous went through a long period of development,the low glass forming ability?GFA?limits the application of alloys in a wide range of engineering.In 2009,Makino et al.first added P and C into the FeSiB amorphous alloy,and improved the glass forming ability and the soft magnetic properties.On the other hand the thermal stability and corrosion resistance of the amorphous alloys decreased.Severe oxidation of FeSiBP/C alloy during heat treatment and corrosion happened in the working environment deteriorate the soft magnetic properties.In this paper FeSiBP bulk amorphous alloy was prepared by copper mold casting system,and FeSiBP/C amorphous alloy ribbon was prepared by single roller rapid quenching.The structure of the alloy was characterized by X-ray diffraction?XRD?,the soft magnetic properties of the alloy were measured by B-H,VSM and impedance analyzer,respectively.Thermodynamic parameters were obtained by differential thermal analysis?DSC?and thermogravimetric analysis?TG?.Domain patterns which obtained from the alloy's surface were observed by Kerr microscope.The surface morphology and oxide composition of the alloy were analyzed by laser scanning confocal microscopy and X-ray photoelectron spectroscopy?XPS?.The corrosion resistance of FeSiBP/C amorphous alloys was studied by electrochemical workstation technology.The relationships between oxidation or corrosion and soft magnetic properties were stablished.The reduction effect of reducing atmosphere heat treatment on the oxidized alloys was investigated.The results show that Fe₇₈Si₄B₁₃P₅ bulk amorphous with the dimeter of 1.5mm can be prepared by casting method.Thus the addition of P can effectively improve the GFA of the alloy.The supercooled liquid region width is 30 K.With the addition of P or C,the Curie temperature?T_c?and crystallization temperature?T_x?decreased.Meanwhile,the coercive force?Hc?and the saturation magnetic induction intensity?Bs?decreased,the effective permeability??e?increased,and the optimal heat treatment range becomes wide.After heat treatment,the domain patterns becomes order.The addition of P and C also makes the oxidation resistance and corrosion resistance decreasing and deteriorates the soft magnetic properties.The soft magnetic properties of alloy after annealing in air are better than annealed in vacuum for 10 min.The XPS results showed that FeO,Fe₂O₃,Fe₃O₄ and SiO were uniformly distributed on the surface of the alloy resulting in the damage of the soft magnetic properties.The surface oxides were reduced after heat treatment in H₂-Ar atmosphere and the Hc recovered from 8.2 to 1.6A/m.H₂-Ar atmosphere can prevent oxidation in the process of heat treatment and reshed the oxidizeds which provide theoretical guidance for industrial production promoting the development of amorphous alloys.