Fe基块体金属玻璃的结构非均匀性与磁各向异性的关系研究

项目名称： Fe基块体金属玻璃的结构非均匀性与磁各向异性的关系研究

项目编号： No.50871105

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 电工技术

项目作者： 李福山

作者单位： 郑州大学

项目金额： 35万元

中文摘要： 目前金属玻璃结构的非均匀性及其对材料性能的影响引起了国内外学者浓厚的研究兴趣，其力学行为与结构非均匀性的相关性正成为该领域研究热点。本基金项目则是系统地探讨研究了Fe基金属玻璃磁性能与结构非均匀性的关系。一般认为，Fe基金属玻璃由于其单一的非晶结构，从磁学特性看属于各向同性，其磁导率较高。而且由于其磁性来自于原子磁矩，不存在阻止畴壁移动的障碍物（晶粒边界、位错等）,因此其矫顽力较小。但本项研究表明：Fe基BMG虽说是由单一的非晶相构成，其主要软磁性能并不优于相同成分的玻璃条带，这是由于受制备条件及形成特征的影响，所形成的非晶相短程有序化程度不同，自由体积的聚集和分布不同，形成结构的非均匀性， 由此实际的Fe基BMG都具有不同程度的磁各向异性，而此各向异性强烈地控制着其相应的软磁性能。Fe基BMG由短程有序（SRO）发展的结构非均匀性改善对于热激活的方式退火热处理是不敏感的，说明是稳定的；而内应力起伏对于结构弛豫是敏感的，即通过适当的热处理可以在很大程度上得到减小，局域磁各向异也减小。提出了制备铸态下具有良好软磁性能带状金属玻璃的关键技术，为开发无退火软磁非晶带材提供了理论基础。

中文关键词： Fe基合金；块体金属玻璃；结构非均匀性；磁各向异性

英文摘要： In present, the effect of structural inhomogeneity of metallic glass on its performance has attracted thick researching interests of researcher home and abroad. The mechanical behaviors ralated to structural inhomogeneity of bulk metallic glass is becoming hot researching point in this field. The project funded by National Natural Science Foundation of China (NSFC) is aimed at systematically invetigating the correlation between structural inhomogeneity and magnetic properties for metallic glass Fe-based metallic glass. In general, the ferromagnetic magnetization vector is supposed to be free from any special anisotropy. However, the present researches indicate that most Fe-based BMG ferroagnets behave anisotropically in different degrees. As a result, some soft magnetic properties of real Fe-based BMG materials are no better than those of conventional Fe-based metallic glassy ribbons as anticipated. There are remarkable differences between the cooling rates for of Fe-based bulk metallic glass prepared by copper mold casting and for conventional Fe-based metallic glassy ribbon prepared by melt-spinning, which results in innegligible differences in structure between them. Accordingly Fe-based bulk metallic glass exhibits distinct magnetic anisotropy compared with conventional Fe-based metallic glassy ribbon. The induced anisotropy are the important factor by which some main soft magnetic properties of real Fe-based BMG materials are strongly governed.The structural inhomogeneity is caused by the special short-range order (SRO) and in the microstructure induced by subtle rearrangement of atoms in BMG materials， which is affected by fabrication condition and formation feature.Further researching shows that the structural inhomogeneity of Fe-based metallic glass is insensitive to heating treatment of activation heat, indicating that the structural inhomogeneity is stable. On the contrary, internal stress is sensitive to heating treatment. In the research, the interpretation of the structure mechanism and physical nature of magnetic anisotropy for Fe-based BMGs is elicited, and theory principle for fabricating Fe-based metallic glass is proposed.

英文关键词： Fe-based alloy; bulk metallic glass; structural inhomogeneity; magnetic anisotropy