TY - JOUR
T1 - Zircon formation from amorphous powder and melt in the silica-rich region of the alumina-silica-zirconia system
AU - Popa, Mónica
AU - Kakihana, Masato
AU - Yoshimura, Masahiro
AU - Calderón-Moreno, José M.
N1 - Funding Information:
This work is funded by CICYT, Grant MAT2004-01214, and Generalitat de Catalunya Grant 2001-SGR-00190.
PY - 2006/12/15
Y1 - 2006/12/15
N2 - Chemically homogeneous amorphous powders were prepared by sol-gel method from alkoxide mixtures in the silica-rich region of the alumina-silica-zirconia system. A glass with the same composition was obtained by quenching in water from the melt. The evolution with temperature in the range up to 1625 °C was studied by means of X-ray diffraction, infrared and UV-Raman spectroscopy, scanning electron microscopy and energy-dispersive X-ray analysis. Zircon crystallization and stability at temperatures higher than the liquidus temperature were confirmed in both melt-quenched and gel-glasses. Crystallization of cristobalite from the amorphous gel-glasses was observed above 1200 °C. The crystallization of zircon particles was observed after thermal treatment at 1550 °C. At 1625 °C zircon was the only stable crystalline phase due to the complete melting of the silica-rich matrix. The XRD pattern of the ternary gel treated at 1625 °C shows clearly the disappearance of the cristobalite phase, while at 1550 °C there is already partial melting. These results can help to determine the phase equilibrium in the ternary system.
AB - Chemically homogeneous amorphous powders were prepared by sol-gel method from alkoxide mixtures in the silica-rich region of the alumina-silica-zirconia system. A glass with the same composition was obtained by quenching in water from the melt. The evolution with temperature in the range up to 1625 °C was studied by means of X-ray diffraction, infrared and UV-Raman spectroscopy, scanning electron microscopy and energy-dispersive X-ray analysis. Zircon crystallization and stability at temperatures higher than the liquidus temperature were confirmed in both melt-quenched and gel-glasses. Crystallization of cristobalite from the amorphous gel-glasses was observed above 1200 °C. The crystallization of zircon particles was observed after thermal treatment at 1550 °C. At 1625 °C zircon was the only stable crystalline phase due to the complete melting of the silica-rich matrix. The XRD pattern of the ternary gel treated at 1625 °C shows clearly the disappearance of the cristobalite phase, while at 1550 °C there is already partial melting. These results can help to determine the phase equilibrium in the ternary system.
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U2 - 10.1016/j.jnoncrysol.2006.08.033
DO - 10.1016/j.jnoncrysol.2006.08.033
M3 - Article
AN - SCOPUS:33751168476
VL - 352
SP - 5663
EP - 5669
JO - Journal of Non-Crystalline Solids
JF - Journal of Non-Crystalline Solids
SN - 0022-3093
IS - 52-54
ER -