Full metadata record
DC Field | Value | Language |
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dc.contributor.author | Jang, Ye Ryeong | - |
dc.contributor.author | Kim, Tae-Hoon | - |
dc.contributor.author | Kim, Jeongmin | - |
dc.contributor.author | Lee, Hyun-Sook | - |
dc.contributor.author | Lee, Kyungmi | - |
dc.contributor.author | Roh, Jong Wook | - |
dc.contributor.author | Jang, Tae-Suk | - |
dc.contributor.author | Lee, Wooyoung | - |
dc.date.accessioned | 2024-09-12T11:10:14Z | - |
dc.date.available | 2024-09-12T11:10:14Z | - |
dc.date.created | 2024-08-13 | - |
dc.date.issued | 2024-10 | - |
dc.identifier.issn | 1044-5803 | - |
dc.identifier.uri | http://hdl.handle.net/20.500.11750/56880 | - |
dc.description.abstract | We report magnetic and microstructural changes in Nd-Fe-B sintered magnets after the grain boundary diffusion process (GBDP) of low-melting LRE-Al-Cu alloys [LRE (Light Rare-earth) = La and Pr]. A distinctive microstructural feature of the magnets GBD treated with La-Al-Cu (LAC) and Pr-Al-Cu (PAC) were characterized via the electron probe microanalysis and high-angle annular dark-field scanning transmission electron microscopy analysis at a depth of 50 μm from the magnet surface. The formation of a thick high-anisotropy Pr-Al-rich shell was clearly observed in the PAC-GBDP magnets, whereas there was no distinct shell formation in the LAC-GBDP magnets. La, Al, and Cu were dissolved in the Nd-rich grain boundary phase (GBP) rather than in the main phase, thereby thickening the GBP. This resulted in a difference in the coercivity gain between PAC-GBDP (+6.4 kOe) and LAC-GBDP (+3.3 kOe). The point to note here is that the remanence reduction induced by LAC-GBDP (−0.2 kG) is much smaller than that induced by PAC-GBDP (−1.2 kG) because the grain boundary diffused La-Al-Cu, which can dilute the saturation magnetization of the Nd2Fe14B (2–14-1) crystal, does not dissolve into 2–14-1. Furthermore, the squareness of demagnetization curves of the LAC-GBDP magnets (98%) was much improved than that of the PAC-GBDP magnets (86%). This is because chemically induced liquid film migration (CILFM), an undesirable grain growth phenomenon induced by shell formation, does not occur in LAC-GBDP magnets. In conclusion, the deterioration in remanence and squareness, which are serious problems in the LRE-GBDP, can be minimized by the LAC-GBDP; thus, the utilization of La in the GBDP is a promising method for obtaining a high maximum energy product of the magnets. Based on the results of this analytical work, we propose a guide for developing a cost-effective novel GBDP source that can prevent grain growth by CILFM and increase the magnetocrystalline anisotropy of the shell. © 2024 | - |
dc.language | English | - |
dc.publisher | Elsevier | - |
dc.title | Microstructure of shell and grain boundary phase in Nd-Fe-B sintered magnets grain boundary diffusion processed with low-melting LRE-Al-Cu (LRE = La and Pr) alloys | - |
dc.type | Article | - |
dc.identifier.doi | 10.1016/j.matchar.2024.114249 | - |
dc.identifier.wosid | 001295806400001 | - |
dc.identifier.scopusid | 2-s2.0-85200994994 | - |
dc.identifier.bibliographicCitation | Materials Characterization, v.216 | - |
dc.description.isOpenAccess | FALSE | - |
dc.subject.keywordAuthor | Nd-Fe-B | - |
dc.subject.keywordAuthor | Grain boundary diffusion | - |
dc.subject.keywordAuthor | Light rare-earth | - |
dc.subject.keywordAuthor | LRE-Al-Cu | - |
dc.subject.keywordAuthor | Chemically induced liquid film migration | - |
dc.subject.keywordPlus | COERCIVITY ENHANCEMENT | - |
dc.subject.keywordPlus | LIQUID-FILMS | - |
dc.subject.keywordPlus | ELEMENTS | - |
dc.subject.keywordPlus | HEAT | - |
dc.subject.keywordPlus | CHEMICALLY-INDUCED MIGRATION | - |
dc.citation.title | Materials Characterization | - |
dc.citation.volume | 216 | - |
dc.description.journalRegisteredClass | scie | - |
dc.description.journalRegisteredClass | scopus | - |
dc.relation.journalResearchArea | Materials Science; Metallurgy & Metallurgical Engineering | - |
dc.relation.journalWebOfScienceCategory | Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Materials Science, Characterization & Testing | - |
dc.type.docType | Article | - |
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