Koruza, Jurij ; Malič, Barbara (2014)
Initial stage sintering mechanism of NaNbO3 and implications regarding the densification of alkaline niobates.
In: Journal of the European Ceramic Society, 34 (8)
doi: 10.1016/j.jeurceramsoc.2014.01.035
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
The behavior of submicron- and nano-sized NaNbO3 powder compacts during conventional sintering was studied using optical dilatometry and microstructure analysis. Microstructure-development trajectories revealed the dominance of grain growth during the initial sintering stage, while densification occurred only during later stages. Surface diffusion with low activation energy in the range of 50–60 kJ/mol was found to be the dominant material-transport mechanism during the initial sintering stage. The early activation of surface diffusion reduced the sintering driving force, decreased the rate of the densifying mechanisms and was thus identified as the main cause for poor densification of NaNbO3. Same explanation could be valid also for other alkaline niobate based lead-free piezoelectric ceramics. Finally, alternative sintering methods are discussed and the efficiency of the pressure-assisted sintering was demonstrated in successful production of highly-dense fine-grained NaNbO3 ceramics, with relative density and grain size of 98% and 700 nm, respectively.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2014 |
| Autor(en): | Koruza, Jurij ; Malič, Barbara |
| Art des Eintrags: | Bibliographie |
| Titel: | Initial stage sintering mechanism of NaNbO3 and implications regarding the densification of alkaline niobates |
| Sprache: | Englisch |
| Publikationsjahr: | August 2014 |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Journal of the European Ceramic Society |
| Jahrgang/Volume einer Zeitschrift: | 34 |
| (Heft-)Nummer: | 8 |
| DOI: | 10.1016/j.jeurceramsoc.2014.01.035 |
| Kurzbeschreibung (Abstract): | The behavior of submicron- and nano-sized NaNbO3 powder compacts during conventional sintering was studied using optical dilatometry and microstructure analysis. Microstructure-development trajectories revealed the dominance of grain growth during the initial sintering stage, while densification occurred only during later stages. Surface diffusion with low activation energy in the range of 50–60 kJ/mol was found to be the dominant material-transport mechanism during the initial sintering stage. The early activation of surface diffusion reduced the sintering driving force, decreased the rate of the densifying mechanisms and was thus identified as the main cause for poor densification of NaNbO3. Same explanation could be valid also for other alkaline niobate based lead-free piezoelectric ceramics. Finally, alternative sintering methods are discussed and the efficiency of the pressure-assisted sintering was demonstrated in successful production of highly-dense fine-grained NaNbO3 ceramics, with relative density and grain size of 98% and 700 nm, respectively. |
| Freie Schlagworte: | Sintering; Microstructure; Lead-free; Piezoceramics; Alkaline niobates |
| Fachbereich(e)/-gebiet(e): | Studienbereiche |
| Hinterlegungsdatum: | 09 Dez 2014 13:31 |
| Letzte Änderung: | 09 Dez 2014 13:31 |
| PPN: | |
| Sponsoren: | This research was financially supported by the Slovenian Research Agency (Young Researcher program, Contract Nos. 1000-08-310121 and P2-0105). |
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