Densification and grain growth in BaTiO3 ceramics fabricated from nanopowders synthesized by ball-milling assisted hydrothermal reaction
✍ Scribed by Yuji Hotta; Cihangir Duran; Kimiyasu Sato; Takaaki Nagaoka; Koji Watari
- Publisher
- Elsevier Science
- Year
- 2008
- Tongue
- English
- Weight
- 572 KB
- Volume
- 28
- Category
- Article
- ISSN
- 0955-2219
No coin nor oath required. For personal study only.
✦ Synopsis
BaTiO 3 powders synthesized by hydrothermal reaction assisted with or without ball milling were used to fabricate sintered bulk BaTiO 3 ceramics. The sintering rate of BaTiO 3 green compacts produced by ball-milling assisted hydrothermal reaction was found to be faster than that prepared by hydrothermal reaction without ball milling. In the case of green compacts produced by BaTiO 3 powders synthesized without ball milling, the relative density and the shrinkage of sintered compacts were measured to be 60% and 5% at 900 • C and 94.3% and 13% at 1000 • C, respectively. On the other hand, the relative density and the shrinkage of sintered compacts produced by ball-milling assisted hydrothermal reaction were measured to be 96.5% and 8% at 900 • C and 98.6% and 24% at 1000 • C, respectively. Furthermore, the free energy for grain-growth activation was estimated from the relationship between grain size and sintering temperature. The free energy for grain-growth activation of the sample produced by the hydrothermal reaction assisted with or without ball milling was calculated to be 4.2 × 10 5 and 8.4 × 10 5 J/mol, respectively. It was found that the grain-growth of green compacts produced by assistance of ball milling was promoted at lower-sintering temperature.