Study On Thermodynamic And Soft Magnetic Properties In The Fe-Based Multicomponent Metallic Glasses

In this paper, the Fe-Nb-B amorphous ribbons are successfully prepared by means of melt-spinning method. On this basis, Fe-Nb-B-Mo and Fe-Nb-B-Cr-Ni amorphous alloys are prepared by adding transition metal elements M (M=Mo, Cr, Ni). Alloys’ glass forming ability (GFA) are decided by adopting the combination of thermodynamic model prediction and experimental methods. The glass forming ability(GFA) and soft magnetic properties of these glasses have been systematically studied by X-ray diffraction(XRD), differential scanning calorimetry(DSC) and vibrating sample magnetometer(VSM). The main conclusions of research are as follows:The GFA of those alloys are qualitatively predicted by using thermodynamic model and determines alloys’ composition range with the best GFA.The GFA and soft magnetic properties of the Fe-Nb-B ternary alloys are related to alloys’ composition. Among them, the smallest ΔTx is 30 K and the biggest ΔTx is 84 K. The B element can improve the GFA of Fe-Nb-B ternary alloys. The supercooled liquid region ΔTx(= Tx1-Tg) of alloys is increasing with the increasing of the B contents in Fe-Nb-B ternary alloys.The GFA and soft magnetic properties of Fe-Nb-B-Mo quaternary alloys are dependent on contents of Mo. The part of Nb in Fe6sNb7B28 and Fe80Nb5B15 ternary amorphous alloys are replaced by Mo, so Fe65(Nb0.85Mo0.15)7B28 and Fe80(Nb0.7Mo0.3)5B15 alloys can be obtained. Their ΔTx are respectively 68 K and 43 K.The part of Fe are replaced by Mo and Fe71-xNb6B23Mox(x= 1,3,5) amorphous alloys can be obtained. The crystallization process of the Fe-based amorphous alloys is closely related to the contents of Mo. The crystallization transformation of the alloys experiences from the twice crystallization processes to one crystallization process with the contents of Mo increasing from 1 at.% to 5 at.%. The thermal stability is improved and the GFA is reduced. The soft magnetic property of Fe71-xNb6B23Mox amorphous ribbons is good and the saturation magnetization(Ms) change between 60 emu/g and 84 emu/g. The outer valence electrons of Mo atom and the 3d electronic layer of magnetic Fe atom form antiferromagnetic coupling and it leads to reducing of alloys’Ms. Fe70Nb6B23Mo1 alloy has the best GFA and excellent soft magnetic property.On basis of the Fe80Nb5B15 ternary alloy, Fe-Nb-B-Cr-Ni multicomponent amorphous alloys are prepared by adding transition metal elements M (M=Mo, Cr, Ni). The results indicate that the part of Fe replaced by Cr and Ni can improve the GFA, but reduce the soft magnetic property of alloys. The ΔTx of (Fe1-x-yNixCry)80Nb5B15 (x=0.1, y=0.1; x=0.05, y= 0.1; x=0.1, y=0.05; x=0.05, y=0.05) change between 39 K and 59 K and are larger than ΔTx (= 24 K) of no adding Cr, Ni alloys. When adding the same contents of Ni, alloys’ the saturation magnetization(Ms) reduces with increasing of Cr contents. The Ms of (Fe0.85Ni0.05Cr0.05)80Nb5B15 amorphous alloy is 75 emu/g but the Ms of (Fe0.8Ni0.1Cr0.1)80Nb5B15 amorphous alloy is only 19 emu/g.