| 보헤마이트 졸겔법에 의한 알루미나 세라믹스의 저온소결 I. 상전이 및 소결거동 |
| 이형민, 이홍림 |
| 연세대학교 세라믹공학과 |
| Low Temperature Sintering of Alumina by Boehmite Sol-Gel Method I. Phase Transformation and Sintering Behavior |
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| ABSTRACT |
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Dry gel composed of primary particles more homogeneous than starting boehmite powder was prepared by dispersing and gelling the boehmite powder. The transformation temperatures of boehmite powder, dry gel seeded with 0, 1, 3, 5 wt% $alpha$-Al2O3, and ball milled gel were 1192$^{circ}C$, 1184$^{circ}C$, 1141$^{circ}C$, 1119$^{circ}C$, 1117$^{circ}C$, and 1106$^{circ}C$, respectively. Sintering behavior of dry gel without seed was similar to that of boehmite powder, but the sintered density of dry gel was improved as much as 10%~15% than boehmite powder. In the case of dry gel seeded with 5 wt% $alpha$-Al2O3, sintering behavior was much improved. The relative density of the gel seeded with 5 wt% $alpha$-Al2O3 was 96% when sintered at 140$0^{circ}C$ for 1h. On the other hand, ball milling of the non-seeded sol for 48h resulted in the relative density of 97% when sintered at 130$0^{circ}C$ for 1h. The size and amount of $alpha$-Al2O3 particles added by ball milling were 0.107 ${mu}{textrm}{m}$ and 0.5 wt%. |
| Key words:
Boehmite, Transformation temperature, Dry gel, $\alpha$-$Al_2O_3$ seed, Sintered density, Ball milling |
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