Thermal oxidation of β-sialon (Si6-zAlzO zN8-z, z = 3) ceramic was investigated at 1300 to 1600°C in dry (Ar/O2= 90/10 kPa), wet O2 (Ar/O 2/H2O = 80/10/10 kPa) and wet (Ar/H2O = 90/10 kPa) atmospheres. Oxidation was followed from weight gains using thermogravimetry and the oxidized sample was characterized by scanning electron microscope, electron probe microanalysis and X-ray powder diffraction. Oxidation kinetics in the three atmospheres were represented by a parabolic rate model except for at 1600°C. The wet and wet O2 oxidation rates were greater than the dry oxidation, the degree decreasing with rising temperature from 1300 to 1500°C, while wet and wet O2 oxidation at 1600°C was even faster again than the dry oxidation. It was found that the scale formed by the dry, wet and wet O2 oxidation consisted of mullite and cristobalite at 1300-1500°C and of mullite and SiO2 rich aluminosilicate glass at 1600°C.
|ジャーナル||Key Engineering Materials|
|出版ステータス||Published - 2004 1 1|
|イベント||Proceedings of the 8th Conference and Exhibition of the European Ceramic Society - Istanbul, Turkey|
継続期間: 2003 6 29 → 2003 7 3
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