method of producing a ceramic material based on sialon by reduction of a alumosilikat - land and its use for the ceramic coating of a refractory substrate

摘要

A ceramic material based on Sialon, especially ss'-Sialon, is obtained by reduction of an aluminosilicate precursor with a gaseous phase comprising a mixture of hydrogen and of nitrogen doped with a carbon compound. The carbon compound is a gas containing carbon in combined form, for example an alkane, and its proportion by volume in the gaseous phase is lower than 3 %. The process is especially suitable for forming Sialon-based coatings on bulk or fibrous substrates. In the case of composite materials consisting of a fibrous preform densified with a matrix, the process makes it possible to form an interphase coating on the fibres of the preform before the latter is densified, or else to form a Sialon-based matrix.