Study on narocrystalline Fe-based alloys with high saturation magnetization

我们对1.6 T以上高饱和磁化强度（Bs）的铁基软磁材料的开发进行了基础研究。结果发现，Fe-Co-Zr-Nb-B体系中非晶相部分结晶得到的纳米级bcc相合金具有1.6 T以上的高Bs、1kHz时10^5的极高磁导率和接近于零的磁致伸缩（lambdas）。确定了最适宜的成分为Fe-2at%Co-2%Zr-5%Nb-5%B。使用该组件，可以通过单辊淬火技术生产宽度为12毫米，厚度为20毫米，长度超过100米的长宽非晶片。该非晶片具有良好的弯曲延展性，并通过机械冲孔制备了直径为10 mm的环形样品。在873 K下退火3.6 K，形成了由直径为10 ~ 20 nm的bcc颗粒和厚度约为5 nm的…More非晶相组成的纳米晶结构。纳米束成分分析表明，Co元素在bcc颗粒中富集，而Zr、Nb和B元素则向非晶相分离。组成元素的重新分配是形成纳米晶结构的必要条件，从而形成具有良好软磁性能和高Bs的材料。我们还指出，bcc颗粒的粒径和颗粒间距小于磁畴壁的宽度，纳米级的混合结构使交换相互作用成为铁磁性的表现。随后，用环氧树脂对纳米晶环形片进行了层合，并测量了层合片在50 Hz至10 MHz范围内的芯损耗和模态随频率的变化。结果表明，与传统的Fe-3质量%Si钢和Fe-Si-B非晶片相比，由于同时满足高Bs和零λ，层合板具有更好的软磁性能。因此，目前的纳米级bcc合金有望成为一种新型的高硼软磁材料。少

We carried out the fundamental study on the development of Fe-based soft magnetic materials with high saturation megnetization (Bs) above 1.6 T.As a result, the nanoscale bcc phase alloys obtained by partial crystallization of an amorphous phase in Fe-Co-Zr-Nb-B system were found to exhibit high Bs above 1.6 T,extremely high permeability (mue) of 10^5 at 1kHz and nearly zero magnetostriction (lambdas). The most appropriate composition was determined to be Fe-2at%Co-2%Zr-5%Nb-5%B.The use of this component enabled the production of long and wide amorphous sheets with 12 mm in width, 20 mum in thickness and more than 100 m in length by the single-roller quenching technique. This amorphous sheet had good bend ductility and ring-shape samples with 10 mm in diameter were prepared by mechanical punching. The annealing of the ring-shape samples for 3.6 ks at 873 K caused the formation of the nanocrystalline structure consisting of bcc particles with a diameter of 10 to 20 nm surrounded by the … More amorphous phase with a thickness of about 5 nm. The nanobeam compositional analyzes indicate that the Co element is enriched in the bcc particles while the Zr, Nb and B elements are segregated to the amorphous phase. The redistribution of the constituent elements was essential for the formation of the nanocrystalline structure leading to the appearance of the good soft magnetic properties combined with high Bs. We also pointed out that the particle size and interparticle spacing of the bcc particles were smaller than the width of magnetic domain wall and the nanoscale mixed structure enabled the achievement of the exchange interaction for the appearance of ferromagnetism. Subsequently, the nanocrystalline ring-shape sheets were laminated with epoxy resin for the purpose of application, and the core losses and mue as a function of frequency in a range of 50 Hz to 10 MHz were measured for the laminated sheets. As a result, the laminated sheets were found to exhibit much better soft magnetic properties as compared with those for conventional Fe-3 mass%Si steel and Fe-Si-B amorphous sheets because of the simultaneous satisfaction of high Bs and zero lambdas. Consequently, the present nanoscale bcc alloys are expected to be used as a new type of soft magnetic material with high Bs. Less