Microstructure evolution of hot-deformed SmCo-based nanocomposites induced by thermo-mechanical processing  

作　　者：Yuan Teng Yuqing Li Xiaochang Xu Ming Yue Weiqiang Liu Dongtao Zhang Hongguo Zhang Qingmei Lu Weixing Xia 

机构地区：[1]Faculty of Materials and Manufacturing,Key Laboratory of Advanced Functional Materials,Ministry of Education of China,Beijing University of Technology,Beijing 100124,China [2]Key Laboratory of Magnetic Materials and Devices,Ningbo Institute of Material Technology and Engineering,Chinese Academy of Sciences,Ningbo 315201,China

出　　处：《Journal of Materials Science & Technology》2023年第7期193-202,共10页材料科学技术（英文版）

基　　金：This work was financially supported by the National Key R&D Program of China(No.2021YFB3500300);the National Natural Science Foundation of China(Nos.51931007,51871005,and 51801005);the Key Program of Science and Technology Development Project of Beijing Municipal Education Commission of China(No.KZ202010005009);the Chaoyang District Postdoctoral Research Foundation(No.2021ZZ-36);the International Research Cooperation Seed Fund of Beijing University of Technology(No.2021B23).

摘　　要：Nanocomposite permanent magnets have ultra-high theoretical magnetic energy products,due to cou-pling of the soft/hard magnetic phases,inciting strict microstructural requirements.In this study,the microstructure evolution,including the phase transition,morphological changes,and texture formation,of hot-deformed SmCo-based nanocomposites under thermal-stress-strain coupling was characterized to determine a possible strategy for achieving high performance.The SmCo_(5)/α-Fe nanocomposites precursor contained fine and dispersed Sm(Fe,Co)_(5)and Fe-Co grains and exhibited a two-stage phase transforma-tion accompanied by grain growth.In the early stage of deformation at relatively low temperature,the adjacent Sm(Co,Fe)5 and Fe-Co phase formed the Sm_(2)(Co,Fe)_(17)-H phase,which was stable only with small grain sizes.In the high-temperature deformation stage,the Sm_(2)(Co,Fe)_(17)-H phase transformed into the Sm_(2)(Co,Fe)_(17)-R phase with large grain sizes.In addition,the strong c-axis texture formed in the Sm(Co,Fe)_(5)phase but not in the Sm_(2)(Co,Fe)_(17)-R phase.Subsequently,the phase transition process and texture formation mechanism were systematically analyzed by transmission electron microscopy.The ini-tiation of a slip system and/or preferential grain growth explained the formation of texture under the action of uniform stress and strain and assisted by dispersed Sm-rich nanograins.The Sm_(2)(Co,Fe)_(17)-R grains with poor orientations and large grain sizes did not achieve magnetic hardening,which also dam-age the magnetic properties.According to the results of this work,we also presented a new strategy to prepare high-performance SmCo-based nanocomposites magnets.

关 键 词：NANOCOMPOSITES Phase transition Microstructure C-axis texture Hot deformation 

分 类 号：TQ174.758.22[化学工程—陶瓷工业]