Researches On Forming Of FeSiBM Amorphous/Crystalline Alloys With High Saturation Magnetization

With the rapid development of electronic power, energy, communications and other fields, the demand for soft magnetic materials is increasing, and the requirements for its performance are also getting higher and higher. As a new soft magnetic materials, Fe based amorphous and nanocrystalline alloy has the advantages of low coercivity and iron loss compared with traditional soft magnetic materials, therefore it has greater influence on the field of social applications. But the saturation magnetization of the mature amorphous and nanocrystalline alloy is relatively low, which greatly limits its application.In recent years, in order to achieve miniaturization of electronic devices, reduce the cost of materials and the working noise of the transformer, the development of amorphous nanocrystalline with high iron content and high saturation magnetization has become a hot research topic. In this paper, in order to develop FeSiBM system amorphous and nanocrystalline alloy with the excellent properties of high saturation magnetization, element substitution was used in Fe82Si5B13 alloy and increase the iron content to change the composition of the alloy, so as to improve the properties of the alloy.In this paper, FeSiBM series of amorphous nanocrystalline alloy samples were prepared by the single roll strip casting. To study the micro structure, thermal properties, soft magnetic properties, surface morphology and its mechanical properties of the samples, having XRD, DSC, VSM and SEM test for them. The results shows that with the addition of Zr, Nb and Mo, the amorphous forming ability of the alloy increases first and then decreases, and continue to enhance the thermal stability. With the increasing of Fe content in the alloy, amorphous formation ability decreases, and thermal stability decreases. But the saturation magnetization is obviously improved. Considering the properties of samples comprehensively, the Fe86Si2B11Mo1 and Fe82Si5B12.5Nb0.5 amorphous nanocrystalline alloys with excellent properties were obtained.The quenched samples of Fe82Si5B12.5Nb0.5 alloy were selected to carry out annealing treatment, and the effect of different annealing treatment on the microstructure and soft magnetic properties of the samples were studied by XRD and VSM. It was found that with the increase of annealing treatment temperature, the degree of crystallization in the amorphous alloy was increased, and the grain size increased. Because the appropriate crystallization is benefit for nanocrystalline alloy magnetic properties, it will deteriorate the properties of the samples, that the degree of crystallization is too strong, and grain is too large.and the saturation magnetization shows the change rules of first increase and then decreases.