- Zr2WP2O12 세라믹스의 합성과 소결거동 연구
- ㆍ 저자명
- 김용현,김남옥,이상진,Kim. Yong-Hyeon,Kim. Nam-Ok,Lee. Sang-Jin
- ㆍ 간행물명
- 한국세라믹학회지
- ㆍ 권/호정보
- 2012년|49권 6호|pp.586-591 (6 pages)
- ㆍ 발행정보
- 한국세라믹학회
- ㆍ 파일정보
- 정기간행물| PDF텍스트
- ㆍ 주제분야
- 기타
$Zr_2WP_2O_{12}$ powder, which has a negative thermal expansion coefficient, was synthesized by a solid-state reaction with $ZrO_2$, $WO_3$ and $NH_4H_2PO_4$ as the starting materials. The synthesis behavior was dependent on the solvent media used in the wet mixing process. The $Zr_2WP_2O_{12}$ powder prepared with a solvent consisting of D. I. water was fully crystallized at $1200^{circ}C$, showing a sub-micron particle size. According to the results obtained from a thermal analysis, a $ZrP_2O_7$ was synthesized at a low temperature of $310^{circ}C$, after which it was reacted with $WO_3$ at $1200^{circ}C$. A new sintering additive, $Al(OH)_3$, was applied for the densification of the $Zr_2WP_2O_{12}$ powders. The cold isostatically pressed samples were densified with 1 wt% $Al(OH)_3$ additive or more at $1200^{circ}C$ for 4 h. The main densification mechanism was liquid-phase sintering due to the liquid which resulted from the reaction with amorphous or unstable $Al_2O_3$ and $WO_3$. The densified $Zr_2WP_2O_{12}$ ceramics showed a relative density of 90% and a negative thermal expansion coefficient of $-3.4{ imes}10^{-6}/^{circ}C$. When using ${alpha}-Al_2O_3$ as the sintering agent, densification was not observed at $1200^{circ}C$.