Fabrication of transparent YAG ceramics by traditional
solid-state-reaction method
solid-state-reaction method
(Center for Composite Materials, Harbin Institute of Technology, Harbin 150001, China)
Abstract: Transparent polycrystalline YAG ceramics were fabricated by solid-state reaction method using commercial ultrafine yttria and α-Al2O3 powders. The starting materials were milled and calcined at 1 400 ℃, and sintered into transparent YAG ceramics at 1 750 ℃ in the vacuum for 4 h. Neither the starting materials as-milled or those calcined into YAG phase at 1 500 ℃ can be sintered into transparent ceramics. Wide grain boundaries emerge in the YAG ceramics sintered at 1 850 ℃ for 4 h, at the edge of which YAG phases decompose into perovskite YAlO3(YAP) and α-Al2O3.
Key words: YAG; α-alumina; yttria; perovskite; sintering