Analytical electron microscopy of corrosion-resistant Nd-(Fe, Co, Ni, Ti)-B magnets

Y. Kitano; J. Shimomura; M. Shimotomai; Y. Fukuda; A. Fujita; Y. Ozaki

doi:10.1016/0925-8388(93)90360-Y

Analytical electron microscopy of corrosion-resistant Nd-(Fe, Co, Ni, Ti)-B magnets

Y. Kitano, J. Shimomura, M. Shimotomai, Y. Fukuda, A. Fujita, Y. Ozaki

Research output: Contribution to journal › Article › peer-review

2 Citations (Scopus)

Abstract

The microstructures of cast ingot, annealed ingots and sintered bodies of Nd₁₅(Fe_0.585Co_0.3Ni_0.1Ti_0.015)₇₇B₈ alloy were investigated with analytical electron microscopes to clarify the changes of the phases with successive processing. Five phases were identified in the specimens, namely Nd₂(Fe_0.6Co_0.3Ni_0.1)₁₄B, Nd(Fe_1-x-yCo_xNi_y)₄B, Nd(Ni_1-xCo_x), Nd(Fe_1-x-yCo_xNi_y)₂ and TiB₂. In addition, (Nd_1-yTM_y)₂O₃ (TM Fe, Ni, Co) phase was also identified in the sintered specimen. An Nd-rich phase was not observed in the present specimens. The phases, except the main magnetic phase (Nd₂TM₁₄B), were different in crystal structure from those in ternary Nd-Fe-B magnets. The majority of NdTM₄B dissolved to supply B atoms to TiB₂ during the sintering. Some of the Nd(Ni_1-xCo_x) phase reacted with O atoms absorbed during the milling and/or sintering process, and formed Nd_1-yTM_y)₂O₃ precipitate during the sintering. The remaining Nd(Ni_1-xCo_x) phase precipitated as thin precipitates at grain boundaries. It is suggested that the phases enriched with Ni and the absence of the Nd-rich phase give rise to the high corrosion resistance of Nd-(Fe, Co, Ni, Ti)-B magnets.

Original language	English
Pages (from-to)	245-248
Number of pages	4
Journal	Journal of Alloys and Compounds
Volume	193
Issue number	1-2
DOIs	https://doi.org/10.1016/0925-8388(93)90360-Y
Publication status	Published - Mar 15 1993
Externally published	Yes

All Science Journal Classification (ASJC) codes

Mechanics of Materials
Mechanical Engineering
Metals and Alloys
Materials Chemistry

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10.1016/0925-8388(93)90360-Y

Cite this

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title = "Analytical electron microscopy of corrosion-resistant Nd-(Fe, Co, Ni, Ti)-B magnets",

abstract = "The microstructures of cast ingot, annealed ingots and sintered bodies of Nd15(Fe0.585Co0.3Ni0.1Ti0.015)77B8 alloy were investigated with analytical electron microscopes to clarify the changes of the phases with successive processing. Five phases were identified in the specimens, namely Nd2(Fe0.6Co0.3Ni0.1)14B, Nd(Fe1-x-yCoxNiy)4B, Nd(Ni1-xCox), Nd(Fe1-x-yCoxNiy)2 and TiB2. In addition, (Nd1-yTMy)2O3 (TM Fe, Ni, Co) phase was also identified in the sintered specimen. An Nd-rich phase was not observed in the present specimens. The phases, except the main magnetic phase (Nd2TM14B), were different in crystal structure from those in ternary Nd-Fe-B magnets. The majority of NdTM4B dissolved to supply B atoms to TiB2 during the sintering. Some of the Nd(Ni1-xCox) phase reacted with O atoms absorbed during the milling and/or sintering process, and formed Nd1-yTMy)2O3 precipitate during the sintering. The remaining Nd(Ni1-xCox) phase precipitated as thin precipitates at grain boundaries. It is suggested that the phases enriched with Ni and the absence of the Nd-rich phase give rise to the high corrosion resistance of Nd-(Fe, Co, Ni, Ti)-B magnets.",

author = "Y. Kitano and J. Shimomura and M. Shimotomai and Y. Fukuda and A. Fujita and Y. Ozaki",

year = "1993",

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doi = "10.1016/0925-8388(93)90360-Y",

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T1 - Analytical electron microscopy of corrosion-resistant Nd-(Fe, Co, Ni, Ti)-B magnets

AU - Kitano, Y.

AU - Shimomura, J.

AU - Shimotomai, M.

AU - Fukuda, Y.

AU - Fujita, A.

AU - Ozaki, Y.

PY - 1993/3/15

Y1 - 1993/3/15

N2 - The microstructures of cast ingot, annealed ingots and sintered bodies of Nd15(Fe0.585Co0.3Ni0.1Ti0.015)77B8 alloy were investigated with analytical electron microscopes to clarify the changes of the phases with successive processing. Five phases were identified in the specimens, namely Nd2(Fe0.6Co0.3Ni0.1)14B, Nd(Fe1-x-yCoxNiy)4B, Nd(Ni1-xCox), Nd(Fe1-x-yCoxNiy)2 and TiB2. In addition, (Nd1-yTMy)2O3 (TM Fe, Ni, Co) phase was also identified in the sintered specimen. An Nd-rich phase was not observed in the present specimens. The phases, except the main magnetic phase (Nd2TM14B), were different in crystal structure from those in ternary Nd-Fe-B magnets. The majority of NdTM4B dissolved to supply B atoms to TiB2 during the sintering. Some of the Nd(Ni1-xCox) phase reacted with O atoms absorbed during the milling and/or sintering process, and formed Nd1-yTMy)2O3 precipitate during the sintering. The remaining Nd(Ni1-xCox) phase precipitated as thin precipitates at grain boundaries. It is suggested that the phases enriched with Ni and the absence of the Nd-rich phase give rise to the high corrosion resistance of Nd-(Fe, Co, Ni, Ti)-B magnets.

AB - The microstructures of cast ingot, annealed ingots and sintered bodies of Nd15(Fe0.585Co0.3Ni0.1Ti0.015)77B8 alloy were investigated with analytical electron microscopes to clarify the changes of the phases with successive processing. Five phases were identified in the specimens, namely Nd2(Fe0.6Co0.3Ni0.1)14B, Nd(Fe1-x-yCoxNiy)4B, Nd(Ni1-xCox), Nd(Fe1-x-yCoxNiy)2 and TiB2. In addition, (Nd1-yTMy)2O3 (TM Fe, Ni, Co) phase was also identified in the sintered specimen. An Nd-rich phase was not observed in the present specimens. The phases, except the main magnetic phase (Nd2TM14B), were different in crystal structure from those in ternary Nd-Fe-B magnets. The majority of NdTM4B dissolved to supply B atoms to TiB2 during the sintering. Some of the Nd(Ni1-xCox) phase reacted with O atoms absorbed during the milling and/or sintering process, and formed Nd1-yTMy)2O3 precipitate during the sintering. The remaining Nd(Ni1-xCox) phase precipitated as thin precipitates at grain boundaries. It is suggested that the phases enriched with Ni and the absence of the Nd-rich phase give rise to the high corrosion resistance of Nd-(Fe, Co, Ni, Ti)-B magnets.

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JO - Journal of Alloys and Compounds

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ER -

Analytical electron microscopy of corrosion-resistant Nd-(Fe, Co, Ni, Ti)-B magnets

Abstract

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