Features of corrosion resistance of AlN-SiC ceramics in air up to 1600°C

• Published in: Journal of the European Ceramic Society Vol. 18; no. 16; pp. 2339 - 2343
• Main Authors: LAVRENKO, V. A, DESMAISON-BRUT, M, PANASYUK, A. D, DESMAISON, J
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Oxford Elsevier 01.12.1998
• Subjects: Applied sciences; Building materials. Ceramics. Glasses; Ceramic industries; Chemical industry and chemicals; Exact sciences and technology; Structural ceramics; Technical ceramics; Aluminium Nitrides; Silicon Carbides; Oxidation; High temperature; Experimental study; Solid solution; Non oxide ceramics; Structural ceramic
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/S0955-2219(98)00240-4

The oxidation kinetics of 80% AlN + 20% SiC and 50% AlN + 50% SiC powders in air up to 1600 C were studied. The ceramics samples were obtained by hot pressing fine-dispersion AlN and SiC powders with an average particle size of 1 micron at 1800 C for 2 h. This ensured a fine-grain material structure with a uniform distribution of phase components. It was shown that in a nonisothermal regime, a three-stage oxidation mechanism takes place. It was established that the scale formed consists of three oxide layers. In the inner layer, Al10N8O2 oxynitride and beta-SiO2 (cristobalite) phases were observed; in the intermediate layer, beta-SiAlON was found for samples with a relatively low SiC content, whereas alpha-Al2O3 was present in samples with a greater SiC content. The outer layer contained 3Al2O3.2SiO2 (mullite) as a main phase, the latter ensuring highly protective properties of the scale. The materials investigated can be considered as having extremely high resistance to corrosion up to 1550 C. 7 refs.