분쇄-침전을 이용한 다결정 YAG 세라믹스의 합성 |
홍석범, 정현기, 심수만 |
홍익대학교 재료공학부 |
Synthesis of Polycrystalline YAG Ceramics by Milling-precipitation |
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ABSTRACT |
Yttrium Aluminum Garnet (YAG) powders were prepared by precipitation of Y hydroxides during milling of alumina powders. The powder calcined at 1200$^{circ}C$ for 4 h contained a small amount of Yttrium Aluminum Monoclinic (YAM) in addition to YAG. However, phase-pure YAG was obtained in the compact of the milled powder with an average particle size of 0.57 ${mu}$m at 1300$^{circ}C$, which is much lower than those (l500∼1600$^{circ}C$) for a mixed oxide method. The powder was found to exhibit an excellent sinterability regardless of the addition of a sintering aid, SiO$_2$(350 ppm Si). The undoped sample were sintered to a relative density of 98% at l600$^{circ}C$. In contrast, the addition of SiO$_2$ caused a considerable densification to occur at 1500$^{circ}C$ and the relative density reached 97.7%. But the sintering aid had little effect on the densification at 1600$^{circ}C$, showing a similar relative density to the undoped sample. |
Key words:
YAG, Polycrystalline, Milling, Precipitation, Sinterability |
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