| AlN-Al2O3 계에서의 상압소결 질화물복합체 |
| 김영우, 김규헌1, 김동현1, 윤석영1, 박홍채1 |
포항산업과학연구원 SOFC연구단
1부산대학교 재료공학부 |
| Pressureless Sintered Nitride Composites in the AlN-Al2O3 System |
| Young Woo Kim, Kyu Heon Kim1, Dong Hyun Kim1, Seog Young Yoon1, Hong Chae Park1 |
SOFC Research Project, Research Institute of Industrial Science and Technology
1School of Materials Science and Engineering, Pusan National University |
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| ABSTRACT |
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Particulate nitride composites have been fabricated by sintering the compacted powder of AlN and 5 - 64.3 mol% $Al_2O_3$, with a small addition of $Y_2O_3$ ($Y_2O_3$/AlN, 1 wt%), in 1-atm nitrogen gas at $1650-1900^{circ}C$. The composites were characterized in terms of sintering behavior, phase relations, microstructure and thermal shock resistance. AlN, 27R AlN pseudopolytype, and alminium oxynitride (AlON, $5AlN{cdot}9Al_2O_3$) were found to existin the sintered material. Regardless of batch composition, the AlN-$Al_2O_3$ powder compacts exhibited similar sintering behavior; however, the degree of shrinkage commonly increased with increasing $Al_2O_3$ content, consequently giving high sintered bulk density. By increasing the $Al_2O_3$ addition up to ${geq}50 mol%$, the matrix phase in the sintered material was converted from AlN or 27R to AlON. Above $1850^{circ}C$, a liquid phase was formed by the reaction of $Al_2O_3$ with AlN, aided by $Y_2O_3$ and mainly existed at the grain boundaries of AlON. Thermal shock resistance was superior in the sintered composite consisting of AlON with dispersed AlN or AlN matrix phase. |
| Key words:
AlN, AlON, Sintering behavior, Thermal shock resistance |
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