Process for anti-oxidation protection of a material of which at least a surface is made of a ceramic formed from a silicon compound, and a material obtained by said process

A material which is protected against oxidation having at least a layer which is composed of a ceramic made from a silicon compound, wherein said material comprises:

• an intermediate layer formed over said layer composed of a ceramic made from a silicon compound, and
• a silica-based vitreous outer layer formed over said intermediate layer,
• wherein said intermediate layer is made of alumina or an alumina precursor and is free of the element silicon so as to constitute a reaction barrier between said silicon compound and said silica-based vitreous outer layer, and to trap silica that may be formed by an oxidation of said silicon compound, whereby anti-oxidation protection is achieved under both an active oxidation condition of said silicon compound and a passive oxidation condition of said silicon compound.