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AssigneeSociete Nationale d'Etude et de Construction de Moteurs d'Aviation
InventorsStephane Goujard, Jean-Luc Charvet, Jean-Luc Leluan, Francois Abbe, Ghislaine Lamazouade
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A composite material protected by oxidation at intermediate temperatures exceeding 850.degree. C. comprises fiber reinforcement densified by a matrix which includes at least one self-healing phase including a glass-precursor component such as B.sub.4 C or an Si--B--C system, together with excess free carbon (C) at a mass percentage lying in the range 10% to 35%. The, or each, self-healing phase can be interposed between two ceramic matrix phases, e.g. of SiC. While the material is exposed to an oxidizing medium, oxidation of the free carbon promotes oxidation of the precursor and transformation thereof into a glass capable of plugging the cracks in the matrix by self-healing.
A composite material protected against oxidation, the material comprising fiber reinforcement densified by a matrix which includes at least one self-healing phase, comprising a component that is a precursor for a glass and that is suitable for forming a glass by oxidation at a temperature that does not exceed 850.degree. C., said glass precursor component including carbon and at least one member of the group consisting of boron and silicon, the material being characterized in that said self-healing phase comprises, at least within the material as formed initially, a mixture of said glass precursor component and of excess free carbon, in which the mass percentage of the free carbon lies in the range of at least 15% to 35% of the mixture.
A method of manufacturing a composite material including protection against oxidation, the method comprising making fiber reinforcement and densifying the reinforcement by means of a matrix comprising at least one self-healing phase including a glass-precursor component suitable for forming a glass by oxidation at a temperature not exceeding 850.degree. C., the method being characterized in that said self-healing phase is made by forming a mixture of said glass-precursor component and of excess free carbon, in which the mass percentage of excess free carbon in the mixture lies in the range of at least 15% to 35%.
A method according to 11, characterized in that densification of the reinforcement comprises forming a plurality of phases having self-healing properties interposed between matrix phases that are better at withstanding oxidation, at least one of the phases having self-healing properties being made by forming a mixture of glass-precursor and of free carbon.
Dependencies are inferred from the claim text.