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Journal of the Korean Ceramic Society 1995;32(4): 482. |
| $gamma$-알루미나부터 $alpha$-알루미나 분말 제조에 있어 Seeding과 알루미나 졸이 미치는 영향 |
| 임경란, 장진욱1, 임창섭, 홍국선1 |
한국과학기술연구원 세라믹스연구부
1서울대학교 무기재료공학과 |
| Effect of $alpha-Al_2O_3$ Seeds and Alumina Sol on $alpha$-Alumina Powder Derived from $gamma-Al_2O_3$ |
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| ABSTRACT |
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The phase transformation temperature from $theta$- to $alpha$-alumina was lowered from 1214$^{circ}C$ to 114$0^{circ}C$ in DSC by treating ${gamma}$-alumina obtained by calcination of boehmite at $700^{circ}C$ for 2hrswith $alpha$-Al2O3 seeds (d50=0.36${mu}{textrm}{m}$) and 3wt% of the alumina sol. $alpha$-Al2O3 seeds seemed to lower to the transformation temperature and the alumina sol suppressed the high temperature agglormeration. The effect was increased as the amount of the sol was increased, which was supported by TEM and particle size distribution. For an example, spherical ${gamma}$-alumina powder with d50=0.54${mu}{textrm}{m}$ was prepared by treating the ${gamma}$-alumina with 9 wt% of the alumina sol and 3wt% of the $alpha$-Al2O3. It sintered to 99% of the theoretical density at 150$0^{circ}C$ for 2hrs. and it had relatively homogeneous microstructure with 2~3${mu}{textrm}{m}$ sized grains. |
| Key words:
$\gamma$-alumina, Seeding, Alumina sol, $\alpha$-Alumina powder |
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