Abstract Sm2Co17-type permanent magnets have important application value due to their advanced magnetic properties, which can be ascribed to their unique cellular structure and element segregation in various phases developed after isothermal aging treatment. In this study, the evolution of the microstructure combined with the microchemistry of Sm2Co17-type magnets from solid solution precursor to the cellular structure is investigated, and a new insight into the formation of the cellular structure is provided. We report for the first time that a large number of strip-like nanoscale short-range ordered micro-domains are distributed in the disordered matrix of the solution precursor, which serve as the nucleation centers in the formation of the embryos of the cellular structure. Based on atomic scale structural analyses, a new mechanism concerning the ordering transformation from short-range 2:17R microtwins to long-range 2:17R phase is proposed, involving collective glide of three partial dislocations on successive basal planes with the net Burgers vector to be zero. Furthermore, microchemistry analysis reveals that the segregation of Cu and Fe in the early stage of isothermal aging is accelerated substantially during the ordering transformation, indicating that the ordering transformation can act as a new driving force for element segregation in Sm2Co17-type magnets. These findings provide new considerations for the development of high performance Sm2Co17-type magnets.

中文翻译：

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Sm2Co17 型磁铁中纳米级短程有序诱导的细胞结构和微化学演化

摘要 Sm2Co17型永磁体由于其独特的蜂窝结构和等温时效处理后形成的各相元素偏析，具有先进的磁性能而具有重要的应用价值。在这项研究中，研究了微观结构的演变以及 Sm2Co17 型磁体从固溶体前驱体到蜂窝结构的微观化学，并提供了对蜂窝结构形成的新见解。我们首次报道了大量条状纳米级短程有序微畴分布在溶液前驱体的无序基质中，它们作为细胞结构胚胎形成的成核中心。基于原子尺度结构分析，提出了一种关于从短程 2:17R 微孪晶到长程 2:17R 相的有序转换的新机制，涉及三个部分位错在连续基面上的集体滑移，净伯格斯矢量为零。此外，微观化学分析表明，等温时效早期Cu和Fe的偏析在有序转变过程中显着加速，表明有序转变可以作为Sm2Co17型磁体中元素偏析的新驱动力。这些发现为开发高性能 Sm2Co17 型磁体提供了新的考虑。涉及三个部分位错在连续基面上的集体滑移，净伯格斯矢量为零。此外，微观化学分析表明，等温时效早期Cu和Fe的偏析在有序转变过程中显着加速，表明有序转变可以作为Sm2Co17型磁体中元素偏析的新驱动力。这些发现为开发高性能 Sm2Co17 型磁体提供了新的考虑。涉及三个部分位错在连续基面上的集体滑移，净伯格斯矢量为零。此外，微观化学分析表明，等温时效早期Cu和Fe的偏析在有序转变过程中显着加速，表明有序转变可以作为Sm2Co17型磁体中元素偏析的新驱动力。这些发现为开发高性能 Sm2Co17 型磁体提供了新的考虑。表明排序转变可以作为 Sm2Co17 型磁体中元素偏析的新驱动力。这些发现为开发高性能 Sm2Co17 型磁体提供了新的考虑。表明排序转变可以作为 Sm2Co17 型磁体中元素偏析的新驱动力。这些发现为开发高性能 Sm2Co17 型磁体提供了新的考虑。