重稀土元素对铁基块体非晶合金过冷液相热稳定性及其磁学性能影响机理研究

项目名称： 重稀土元素对铁基块体非晶合金过冷液相热稳定性及其磁学性能影响机理研究

项目编号： No.51271194

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 一般工业技术

项目作者： 沈宝龙

作者单位： 东南大学

项目金额： 80万元

中文摘要： 铁基块体非晶合金掺杂重稀土元素后，其过冷液相热稳定性和磁学性能都会出现一系列有趣的现象，本项目针对产生这些现象的主要原因- - 短程有序结构的演变展开研究。前期研究表明，重稀土元素能够明显改变铁基块体非晶合金的短程有序结构，致使过冷液相区出现放热现象、初始晶化相发生显著变化以及磁致伸缩明显提高。本项目拟通过调节合金成分，采用穆斯堡尔谱与扩展X射线吸收精细结构谱相结合的方法，研究其短程有序结构、同质异能移、超精细磁场、磁矩和键合性质的变化；利用差示扫描量热仪、X射线衍射、透射电子显微镜等方法，研究不同时间和温度热处理后，合金微观结构的变化及分布情况。通过分析合金短程有序结构的形成和演变过程，从机理上揭示其与非晶形成能力、热稳定性、晶化行为和磁性能的本质联系，为提高材料非晶形成能力，优化磁学性能提供理论依据，最终获得性能更为优异的磁致伸缩传感器芯体材料和纳米双相复合永磁材料。

中文关键词： 铁基块体金属玻璃；重稀土元素；非晶形成能力；力学性能；磁学性能

英文摘要： Fe-based bulk amorphous alloys doped with heavy rare earth elements would exhibit a series of interesting phenomena concerning about thermal stability of supercooled liquid and their magnetic properties. The present project is going to study thoroughly the evolution of short-range ordered (SRO) structure that is responsible for all these phenomena. Previous studies have shown that heavy rare earth elements can significantly change the SRO structure in Fe-based bulk amorphous alloys, which results in the exothermic phenomenon in the supercooled liquid region, the changing of initial crystal phase, and subsequently the improved magnetostriction. In our project, we are intended to explore the changes of SRO structure, the isomer shift, the hyperfine magnetic field, the magnetic moment and bonding properties by firstly adjusting the alloy compositions, and then combining methods of M?ssbauer spectroscopy and extended X-ray absorption fine structure spectroscopy. Moreover, variation of the microstructure and their corresponding distribution after annealing at different time and temperature will be analyzed using differential scanning calorimetry, X-ray diffraction, transmission electron microscopy, et. al. Finally, the essential relationship between SRO structure and the glass forming ability, thermal stability, crys

英文关键词： Fe-based bulk metallic glasses；Heavy rare earth elements；Glass-forming ability；Mechanical properties；Magnetic properties