Electro-discharge sintering of nanocrystalline NdFeB magnets
- This study investigates the compaction of nanocrystalline NdFeB magnet powder by electro-discharge sintering (EDS). On this account, process parameters, microstructure, and the associated magnetic properties of the EDS-densified nanocrystalline NdFeB specimens were investigated by varying the discharge energy \(E_{EDS}\) and compression load \(\it {p}_{EDS}\). Although optimized process parameters could be evaluated, three different microstructures (fully densified zone, insufficiently densified zone, and melted zone) are present in the EDS-compacted specimens. Thereby, volume fractions of these formed three different microstructures determine the resulting mechanical and magnetic properties of the specimens. For all specimens, the intrinsic coercivity \(H_{c,J}\) deteriorates with increasing discharge energy, as the generated Joule heat leads to microstructural changes (grain growth, dissolution of magnetic phases), which reduces the magnetic properties. The compression load has less influence on the coercivity \(H_{c,J}\), as it only affects the initial resistance of the pre-compacted powder loose. The residual induction \(B_{r}\) deteriorates with increasing the discharge energy due to microstructural changes. An increase in the compression load \(\it {p}_{EDS}\) results in an increase in the specimens' density and thus promotes the residual induction \(B_{r}\).
Author: | Lennart LeichORCiDGND, Arne RöttgerORCiDGND, Rene KuchenbeckerGND, Werner TheisenGND |
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URN: | urn:nbn:de:hbz:294-95444 |
DOI: | https://doi.org/10.1007/s10854-020-04562-6 |
Parent Title (English): | Journal of materials science : materials in electronics |
Subtitle (English): | process parameters, microstructure, and the resulting magnetic properties |
Publisher: | Springer Science + Business Media B.V. |
Place of publication: | Dordrecht |
Document Type: | Article |
Language: | English |
Date of Publication (online): | 2022/12/23 |
Date of first Publication: | 2020/10/12 |
Publishing Institution: | Ruhr-Universität Bochum, Universitätsbibliothek |
Volume: | 31 |
First Page: | 20431 |
Last Page: | 20443 |
Note: | Dieser Beitrag ist auf Grund des DEAL-Springer-Vertrages frei zugänglich. |
Institutes/Facilities: | Institut für Werkstoffe, Lehrstuhl Werkstofftechnik |
Institut für Werkstoffe | |
Dewey Decimal Classification: | Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften, Maschinenbau |
open_access (DINI-Set): | open_access |
faculties: | Fakultät für Maschinenbau |
Licence (English): | Creative Commons - CC BY 4.0 - Attribution 4.0 International |