HRTEM studies of grain boundaries in die-upset Nd-Fe-Co-Ga-B magnets
In: Journal of alloys and compounds, Jg. 365 (2004), S. 286-290
academicJournal
- print, 13 ref
Zugriff:
Highly textured magnets of MQU-F material (Nd13.6Fe73.6Ga0.6Co6.6B5.6) were produced by die-upsetting. A remanence B, = 1.39 T, a coercivity μ0jHc = 1.18 T and an energy product (BH)max = 370 kJ m-3 were obtained when using a relatively high degree of deformation (height reduction; 80%). Differential scanning calorimetry measurements reveal, beside an increase of the Curie temperature of the main phase, a substantial decrease of the melting point of the intergranular phase (660°C) in comparison to that of the ternary alloy MQP-A (680°C). The microstructure of the hot-deformed MQU-F material, especially of the intergranular phase, was investigated by high-resolution transmission electron microscopy and energy dispersive X-ray spectroscopy (EDX) in the scanning transmission electron microscopic mode with a subnanometer probe. A very homogeneous distribution of the intergranular phase was observed. The Nd2Fe14B crystals are surrounded by an amorphous Nd-rich phase with a thickness of 0.4 to 2 nm. EDX analysis shows that the grain boundaries are enriched in Nd and Ga. Also, a small amount of Co was detected.
Titel: |
HRTEM studies of grain boundaries in die-upset Nd-Fe-Co-Ga-B magnets
|
---|---|
Autor/in / Beteiligte Person: | KIRCHNER, A ; THOMAS, J ; GUTFLEISCH, O ; HINZ, D ; MÜLLER, K.-H ; SCHULTZ, L |
Link: | |
Zeitschrift: | Journal of alloys and compounds, Jg. 365 (2004), S. 286-290 |
Veröffentlichung: | Lausanne: Elsevier, 2004 |
Medientyp: | academicJournal |
Umfang: | print, 13 ref |
ISSN: | 0925-8388 (print) |
Schlagwort: |
|
Sonstiges: |
|