Sawatzki, Simon ; Schneider, Thorsten ; Yi, Min ; Bruder, Enrico ; Ener, Semih ; Schönfeldt, Mario ; Güth, Konrad ; Xu, Bai-Xiang ; Gutfleisch, Oliver (2018)
Anisotropic local hardening in hot-deformed Nd-Fe-B permanent magnets.
In: Acta Materialia, 147
doi: 10.1016/j.actamat.2017.12.059
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
The diffusion of low-melting Nd-Cu alloys is very effective to increase coercivity in hot-deformed Nd-Fe-B permanent magnets without the use of heavy rare earth and to study the local hardening mechanism, especially the role of the Nd-rich grain boundary on the magnetic decoupling of the Nd-Fe-B grains on the nanoscale. In this study, we found that for a Nd-Cu diffusion parallel to the texture axis the increase in is higher than for a diffusion perpendicular to it and strongly depends on the diffusion depth whereas remanence develops in an inverse manner. We note the following three observations to explain This behavior results from: a) a higher overall Nd and Cu concentration for the parallel diffusion revealed by global energy dispersive X-ray (EDX) maps leading to a distinct change in the broadness of the interaction domains visualized by Kerr microscopy, b) a higher degree of misalignment of the Nd2Fe14B grains observed by electron backscattered diffraction (EBSD), and c) a more effective local hardening on the macroscopic scale governed by dipolar and exchange interactions as modeled by micromagnetic simulations. The misalignment and the incorporation of Nd and Cu also lead to a volume expansion of the magnet of around 0.6–0.8% as proven by in-situ thermo-optical measurements (TOM).
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2018 |
| Autor(en): | Sawatzki, Simon ; Schneider, Thorsten ; Yi, Min ; Bruder, Enrico ; Ener, Semih ; Schönfeldt, Mario ; Güth, Konrad ; Xu, Bai-Xiang ; Gutfleisch, Oliver |
| Art des Eintrags: | Bibliographie |
| Titel: | Anisotropic local hardening in hot-deformed Nd-Fe-B permanent magnets |
| Sprache: | Englisch |
| Publikationsjahr: | 1 April 2018 |
| Verlag: | Elsevier Sciene Publishing |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Acta Materialia |
| Jahrgang/Volume einer Zeitschrift: | 147 |
| DOI: | 10.1016/j.actamat.2017.12.059 |
| URL / URN: | https://doi.org/10.1016/j.actamat.2017.12.059 |
| Kurzbeschreibung (Abstract): | The diffusion of low-melting Nd-Cu alloys is very effective to increase coercivity in hot-deformed Nd-Fe-B permanent magnets without the use of heavy rare earth and to study the local hardening mechanism, especially the role of the Nd-rich grain boundary on the magnetic decoupling of the Nd-Fe-B grains on the nanoscale. In this study, we found that for a Nd-Cu diffusion parallel to the texture axis the increase in is higher than for a diffusion perpendicular to it and strongly depends on the diffusion depth whereas remanence develops in an inverse manner. We note the following three observations to explain This behavior results from: a) a higher overall Nd and Cu concentration for the parallel diffusion revealed by global energy dispersive X-ray (EDX) maps leading to a distinct change in the broadness of the interaction domains visualized by Kerr microscopy, b) a higher degree of misalignment of the Nd2Fe14B grains observed by electron backscattered diffraction (EBSD), and c) a more effective local hardening on the macroscopic scale governed by dipolar and exchange interactions as modeled by micromagnetic simulations. The misalignment and the incorporation of Nd and Cu also lead to a volume expansion of the magnet of around 0.6–0.8% as proven by in-situ thermo-optical measurements (TOM). |
| Freie Schlagworte: | permanent magnet, Nd-Fe-B, Hot-deformation, Grain boundary diffusion process (GBDP), Low melting eutectic |
| Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Funktionale Materialien 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Mechanik Funktionaler Materialien 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Physikalische Metallkunde |
| Hinterlegungsdatum: | 12 Mär 2018 10:10 |
| Letzte Änderung: | 26 Jan 2024 09:21 |
| PPN: | |
| Sponsoren: | We thank Juliane Thielsch for experimental advice on the Kerr-microscopy and the German federal state of Hessen through its excellence program LOEWE ”RESPONSE” for financial support., The authors also greatly acknowledge the access to the Lichtenberg High Performance Computer of TU Darmstadt. |
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