Microstructure and Coercivity of Rare Earth Magnets

稀土磁体的微观结构和矫顽力

• 批准号: 63460199
• 负责人: UMEDA Takateru
• 金额: $ 5.57万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1988
• 资助国家: 日本
• 起止时间: 1988 至 1989
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-63460199/
• 关键词: Nd_2Fe_<14>B; microstructure; metastable grain boundary; coercivity; Sm_2Co_<17>; TbCu_7; TbCu_7; 急冷薄帯; Nd_<15>Fe_<77>B_8合金; 液体急冷法; 準安定相; セル構造; 保磁力; 結晶配向

High coercivity of 23 kOe was obtained on melt-spun Nd_<15>Fe_<77>B_8 ribbons with 40-100 m in thichness. The samples which showed high coercivity contained a new metastable boundary phase with 20-80 nm in width Nd_2Fe_<14>B grains were surrounded with this phase and they formed smooth and coherent interface structures. These microstructures indicated a strong pinning effect on the motion of the domain wall. The new phase was identified by analysis of electron diffraction patterns as a tetragonal structure with lattice constants of a=0.512 nm, and c=0.801 nm. By heat treatment over than 760 K, it was decomposed into fcc-Nd and a small amount of NdFe_4B_4. Interface structures between Nd_2Fe_<14>B and grain boundaries became incohent and also coercivity decreased.The vertical sections of Sm-Co-Cu-Fe quaternary and Sm-Co-Cu-Fe -Zr quinary phase diagrams were determined in composition range from 6 to 16 at%Sm. The 2/17 phase has hexagonal TbCu_7, hexagonal Th_2Ni_<17> and rhombohedral Th_2Zn_<17> type structures. Only alloys with TbCu_7 phase at high temperature have superior magnetic properties with high coercivity. The Sm content with 2/17 single phase of TbCu_7 type structure shifts to the Sm-poor side with addition of Zr.

在熔体旋转的ND_ <15> Fe_ <777> B_8丝带上获得了23个KOE的高强度，具有40-100 m。表现出较高矫正的样品包含一个新的亚稳态边界相，其宽度为20-80 nm ND_2FE_ <14> B晶粒被此相包围，它们形成了光滑，相干的界面结构。这些微观结构表明对域壁的运动有很强的固定作用。通过分析电子衍射模式作为晶格常数为A = 0.512 nm的四方结构，C = 0.801 nm来识别新阶段。通过超过760 K的热处理，将其分解为FCC-ND和少量的NDFE_4B_4。 ND_2FE_ <14> B和晶界之间的界面结构变得不稳定并降低。在组成范围内确定了6至16 at in％Sms的组成范围内确定了SM-CO-CU-CU-FE Quaternary和Sm-Co-Cu-fe-fe-Zr quarion相图的垂直截面。 2/17阶段具有Hexagonal TBCU_7，Hexagonal Th_2ni_ <17>和Rhombohedral TH_2ZN_ <17>键入结构。仅在高温下具有TBCU_7相的合金具有高稳态的优质磁性。添加ZR的TBCU_7类型结构的2/17单相的SM含量转移到SM罚款侧。

项目成果

Yoshio MORITA: "MRS Int'l.Mtg.on Adv.Mats.vol.11." Meterials Research Society, 11 (1989)

Yoshio MORITA：“MRS Intl.Mtg.on Adv.Mats.vol.11。”

岩村栄治: "液体急冷法により作製したNd_<15>Fe_<77>B_8薄帯における準安定粒界相と高保磁力に対する効果" 日本金属学会誌. 54. 111-116 (1990)

Eiji Iwamura：“液体淬火法制备的Nd_<15>Fe_<77>B_8带材对亚稳态晶界相和高矫顽力的影响”日本金属学会学报54. 111-116（1990）。

Eiji Iwamura, Katsuhisa Nagayama, Tosho Suzuki, and Takateru Umeda: "Structure of the New Metastable Grain Boundary Phase in Melt-Spun Nd_<15>Fe_<77>B_8 Ribbons and its Roles on High Coercivity" J.Japan Inst.Metals, 54, pp.111-116, 1990.

Eiji Iwamura、Katsuhisa Nagayama、Tosho Suzuki 和 Takateru Umeda：“熔纺 Nd_<15>Fe_<77>B_8 带中新亚稳态晶界相的结构及其对高矫顽力的作用”J.Japan Inst.Metals，

吉田 裕: 日本金属学会誌投稿予定.

Yutaka Yoshida：预定提交给日本金属学会会刊。

岩村栄治: "液体急冷法による製作したNd_<15>Fe_<77>B_8薄帯における準安定粒界相と高保磁力に対する効果" 日本金属学会誌. 54. 111-116 (1990)

Eiji Iwamura：“液体淬火法生产的Nd_<15>Fe_<77>B_8带材中亚稳态晶界相和高矫顽力的影响”日本金属学会杂志54. 111-116（1990）。