Hot Corrosion of Sintered α‐Sic at 1000°C
- 1 August 1985
- journal article
- Published by Wiley in Journal of the American Ceramic Society
- Vol. 68 (8) , 432-439
- https://doi.org/10.1111/j.1151-2916.1985.tb10170.x
Abstract
The hot corrosion of sintered α‐Sic by thin films of Na2SO4 and Na2CO3 was studied at 1000°C in controlled gas atmospheres. Under all conditions corrosion led to 10 to 20 times the amount of SiO2 formed in pure oxidation after a 48‐h exposure. In addition, small amounts of sodium silicate formed. Melts of Na2SO4/SO3 caused uniform pitting of the Sic substrate; Na2CO3/CO2 melts caused localized pitting and grain‐boundary attack. In all cases the protective SiO2 layer dissolved to form silicate, leading to corrosion. In the sulfate case, free carbon in the Sic promotes this process. In all cases the presence of liquid films is responsible for rapid transport rates and the subsequent rapid reaction.Keywords
This publication has 5 references indexed in Scilit:
- An application of EELS in the examination of inclusions and grain boundaries of a SiC ceramicJournal of Microscopy, 1981
- Transport of Oxidant in Molten Na2 SO 4 in O 2 ‐ SO 2 ‐ SO 3 EnvironmentsJournal of the Electrochemical Society, 1981
- Corrosion of Silicon Carbide in Gases and Alkaline MeltsJournal of the American Ceramic Society, 1976
- Molten Salt Corrosion of SiC and Si3N4 Ceramics‐Journal of the American Ceramic Society, 1976
- Determination of traces of fluorine or sulfur by x-ray analysisAnalytica Chimica Acta, 1968