块体各向异性SmFe12型纳米晶永磁材料的制备和结构控制

SmFe12型化合物具有比Nd2Fe14B更优的内禀磁性。如何制备全致密块体各向异性材料是高性能SmFe12型永磁材料发展面临的关键科学问题。本项目拟采用熔体快淬和高压热压缩变形（HPTC）相结合来控制纳米晶的取向生长，制备块体各向异性SmFe12型纳米晶永磁材料。采用熔体快淬制备(Sm1-y,Zry)(Fe,Co)12-xTix非晶前驱物，然后，采用两步变形策略来控制SmFe12纳米晶的取向成核和生长。研究HPTC变形下非晶前驱物中SmFe12型纳米晶的形成、取向生长以及相演变。研究成分、非晶微结构和变形工艺对SmFe12纳米晶的织构和尺寸的调控；揭示HPTC变形下SmFe12纳米晶织构的形成机制。研究SmFe12型纳米晶材料的界面结构和磁性。建立“工艺/成分－微结构－磁性”的关系，发展高性能块体各向异性SmFe12型永磁材料制备的新原理和新技术，促进高性能永磁材料的发展。

SmFe12 compound has superior intrinsic magnetic properties than Nd2Fe14B. How to make full-density bulk anisotropic materials is the key scientific problem for developing high-performance SmFe12-type permanent-magnet materials. In this project, a combined strategy of melt-pinning technology and High-Pressure Thermal Compression (HPTC) deformation will be employed to introduce the oriented growth of nanocrystals and to produce bulk anisotropic SmFe12-type nanocrystalline permanent-magnet materials. First, (Sm1-y,Zry)(Fe,Co)12-xTix amorphous precursor will be produced using the melt-pinning method. Then, a two-step deformation strategy will be used to control the oriented nucleation and growth of SmFe12 nanocrystals, respectively. The crystallization transformation of amorphous precursor, the formation and preferential growth of nanoscale SmFe12 phase and phase evolutions under the HPTC will be studied. The texture and grain size of SmFe12-type nanograins will be turned using composition, amorphous precursor and deformation processing parameters. The underlying grain-alignment mechanism of SmFe12 nanograins will be revealed. The interfacial structure of fabricated bulk SmFe12-type nanocrystalline materials will be characterized and their magnetic properties will be studied. The "processing and compositions - microstructure - magnetic properties" relationships will be achieved. New methods and strategies will be developed to create high-performance bulk anisotropic SmFe12-type permanent magnets. Our studies will facilitate the development of high-performance permanent magnetic materials.