Abstract
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.
| Original language | English |
|---|---|
| Pages (from-to) | 893-896 |
| Number of pages | 4 |
| Journal | Key Engineering Materials |
| Volume | 264-268 |
| Issue number | II |
| Publication status | Published - 2004 Jan 1 |
| Externally published | Yes |
| Event | Proceedings of the 8th Conference and Exhibition of the European Ceramic Society - Istanbul, Turkey Duration: 2003 Jun 29 → 2003 Jul 3 |
Keywords
- Aluminosilicate glass
- Beta-sialon
- Diffusion limiting rate
- Oxidation
- Water vapor
ASJC Scopus subject areas
- Materials Science(all)
- Mechanics of Materials
- Mechanical Engineering