The Glass Forming Ability and Soft Magnetic Properties of Fe-Mn-Si-B-Nb Amorphous Alloys
| Autor: | Po-Hung Kuo, 郭柏宏 |
|---|---|
| Rok vydání: | 2012 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 100 In this investigation, we explored the effects of a small Niobium(Nb) addition in the glass forming ability and remained the soft magnetic properties of Fe-Mn-Si-B amorphous alloy. Multi-component alloy ribbons with compositions of Fe75Mn3Si10B12-xNbx (X=0、1、2、3 and 4 at.%) were synthesized by the single roller melt-spinning method. To examine the glass transition temperature(Tg), crystallization temperature(Tx) and Curie temperature(Tc), the as-cast ribbons was measured with a differential scanning calorimetry(DSC) at a heating rate of 0.33 K/s. Microstructure were examined by X-ray diffractometer(XRD) and scanning electron microscopy(SEM). The saturation magnetization(Ms) and coercive force(Hc) were examined by a vibrating sample magnetometer(VSM) in an applied magnetic field 7000 Oe. To examine the Curie temperature(Tc) and magnetic phase with a thermal gravimetric analyzer(TMA) at a heating rate of 0.33 K/s and in an applied magnetic field 110 Oe. We could observe that the broaden peaks appered when Nb addition were 0~4 at% by XRD and SEM results. The maximum ΔTx (= Tx-Tg) value was 97 K for the 2 at% Nb addition by DSC analysis. In addition, the Ms decreased from 1.45 T to 1.02 T, and the minimum Hc value was 5.89 A/m for the 2 at% Nb. In condition, the 2 at% Nb addition showed the best glass forming ability, and still keep good soft magnetic properties. Annealing the amorphous ribbons at 350℃ and 450℃, using VSM、XRD and SEM to analyze soft magnetic propertiesand microstructure. It was examined that addition of Nb could inhibit the growth of grain at 450℃. The small addition of Nb was very effective in improving glass-forming ability and remained the soft magnetic properties of Fe-Mn-Si-B alloys. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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