采用Nb含量分别为63.6%,66.5%(质量分数)的两种铌铁通过单辊快淬技术制备了Finemet型纳米晶薄带.应用X射线衍射仪和扫描电子显微镜分析了不同Nb含量的铌铁的物相组成及微观组织形貌,发现Nb含量为66.5%(质量分数)的铌铁中存在明显的共晶组织,而低铌含量的铌铁中则无此现象.同时,对制备的Finemet型母合金中物相构成和微观结构进行了研究,发现合金中α-Fe(Si,B)相的微观结构存在差异.采用Lu-borsky弯曲试验测量薄带的脆性,结果表明,用Nb含量为63.6%(质量分数)的铌铁制备的快淬薄带比铌含量为66.5%(质量分数)的铌铁制备的薄带具有更好的韧性.薄带的软磁性能测试发现,用含63.6%(质量分数)Nb的铌铁制备的快淬薄带磁化强度为126.7 A?m2/kg,高于后者,然而其矫顽力比用含66.5%(质量分数)Nb的铌铁制备的薄带要大.这种性能的差异与原材料以及母合金中组织的形态有关.%In this paper,Finemet-type nanocrystalline ribbons were made with Fe-Nb alloys whose Nb content is 63.6wt% and 66.5wt%,respectively,by the rapid solidification technique using a single-roller melt spinning equipment.The composition of phases and microstructures of different kinds of Fe-Nb alloys were investigated by X-ray diffraction and scanning electron microscopy technique.There were obvious eutectic structures in Fe-Nb alloy of which Nb content was 66.5wt%,while the other hardly had the eutectic structures.At the same time,the composition of phase and microstructure morphology of Finemet-type master alloy were also studied though identical methods.The results showed that there were differences for the microstructure of α-Fe(Si,B) phase between these master alloys.The brittleness of as-spun ribbons were measured by using Luborsky meth-od.The fracture toughness of Fe-Nb alloy with 63 .6 wt% Nb was higher than the one of Fe-Nb alloy with 66.5wt% Nb.As the soft magnetic properties result of samples shown,while the saturation magnetization of as-annealed ribbons made with Fe-Nb alloys with 63.6wt% Nb was as high as 126.7 A?m2/kg,which was higher than the later,and the coercivity of former was also higher than the later.The discrepancies on properties were related with the difference of raw materials and microstructure morphology in master alloys.
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