Long term oxidation behaviour of liquid phase pressureless sintered SiC–AlN ceramics obtained without powder bed
| Autor: | Leandro Beaulardi, Giuseppe Magnani |
|---|---|
| Přispěvatelé: | Beaulardi, L., Magnani, G. |
| Rok vydání: | 2006 |
| Předmět: |
Materials science
Oxide Mineralogy chemistry.chemical_element Mullite Yttrium Atmospheric temperature range Microstructure Cristobalite chemistry.chemical_compound chemistry Diffusione innovazione e trasferimento tecnologico Phase (matter) Materials Chemistry Ceramics and Composites Grain boundary Composite material |
| Zdroj: | Journal of the European Ceramic Society. 26:3407-3413 |
| ISSN: | 0955-2219 |
| Popis: | This paper describes the results of the investigation of the oxidation behaviour of 50 wt.% SiC–50 wt.%AlN composites obtained by means of pressureless sintering with Y 2 O 3 as sintering-aid and without using a powder bed to limit the weight loss. Sintered bodies show high density (>98%T.D.) and the microstructure reveals a matrix composed by SiC–AlN solid solution with Y 10 Al 2 Si 3 O 18 N 4 as grain boundary phase. This material exhibits a parabolic oxidation kinetic in the temperature range 1200–1500 °C. Long term oxidation (200 h) induces the formation of a protective oxide scale, composed by mullite, cristobalite and yttrium disilicide, up to 1400 °C. At higher temperature (1500 °C), SiC oxidation behaviour changes from “passive” to “active” and the oxide layer consequently shows porosity due to the formation of gaseous species like SiO and CO. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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