Abstract: The method comprises forming a coating on the product of composite material to be protected. The coating contains a mixture of a non-oxide refractory ceramic in finely-divided form, at least one refractory oxide in finely-divided form and providing healing properties by forming a glass, and a binder constituted by a polymer that is a precursor of a non-oxide refractory ceramic. The polymer is transformed into a ceramic to obtain a protective layer comprising a non-oxide refractory ceramic phase and a healing phase which together constitute two interpenetrating lattices. After the ceramic precursor polymer has been transformed, a final heat treatment step may be performed at a temperature higher than the softening or melting temperature of the healing phase.

Abstract: A process is provided for obtaining an article which is made of a carbon-containing composite material and which is protected against oxidation. The composite material, which is obtained by densifying a porous fibrous texture with a matrix and which exhibits a residual internal porosity, is impregnated under a vacuum with an alkaline compound in a liquid solution. The article is dried and heat-treated at a temperature sufficient to cause the alkaline compound to line the surfaces of the internal pores, thereby constituting the residual porosity and forming a continuous auto-cicatrizing internal protective coating. An additional external protective layer comprised of a wear- and oxidation-resistant material may be applied.