Abstract: A coated part intended to be mounted in a turbomachine, includes a substrate of composite material with a matrix at least partially of ceramic, and an environmental barrier on the substrate and including (i) a bond coat layer including silicon present on a surface of the substrate, and (ii) an environmental barrier layer covering the bond coat layer, the environmental barrier layer including an inner region of barrier to oxidizing and corrosive species which is not cracked and located on the bond coat layer side, and an outer region, opposite the bond coat layer and covering the inner region, having a network of thermomechanical adaptation cracks having a distance between adjacent cracks included between 10 ?m and 50 ?m and having cracks extending over a depth included between 50% and 95% of the thickness of the environmental barrier layer.

Abstract: A fibrous preform for producing a part made of ceramic matrix composite material. The fibrous preform can include: a fibrous reinforcement having fibers based on silicon carbide; an interphase layer extending around a surface of each of the fibers based on silicon carbide, wherein the interphase layer can be based on boron nitride; a pre-densified layer of silicon carbide located on the interphase layer and having a columnar microstructure, the pre-densified layer having a thickness of between 3 ?m and 20 ?m; and a sacrificial layer located on said pre-densified layer, the sacrificial layer being formed from silicon carbide having an average grain size of between 0.1 ?m and 0.5 ?m.

Abstract: A process for manufacturing a part made of ceramic matrix composite material, the process including infiltrating a pre-densified fibrous structure with a molten infiltration composition including silicon, in order to form a ceramic matrix in a residual porosity of the pre-densified fibrous structure, the pre-densified fibrous structure including a pre-densification matrix including a first silicon carbide layer, a reactive layer including a reactive material that contains carbon and is capable of reacting with the silicon in the infiltration composition, the reactive layer covering the first layer, and a molten silicon wetting layer that is made of silicon carbide or carbon and covers the reactive layer.

Abstract: A method for manufacturing a part of SiC/SiC composite material includes the production of a fibrous preform from silicon carbide fibers; the deposition of an interphase on the fibers of the fibrous preform; a first densification including the formation of a first matrix phase by chemical vapor infiltration with a first matrix precursor including methyltrichlorosilane (MTS); a second densification including the formation of a second matrix phase by chemical vapor infiltration with a second SiC precursor different from the first precursor, the second precursor forming an SiC deposit comprising residual hydrogen and free silicon; and a third densification including the impregnation of the fibrous preform with an impregnation composition containing at least silicon so as to obtain a part made of SiC/SiC composite material.

Abstract: A method for manufacturing a part of SiC/SiC composite material includes the production of a fibrous preform from silicon carbide fibers; the deposition of an interphase on the fibers of the fibrous preform; a first densification including the formation of a first matrix phase by chemical vapor infiltration with a first matrix precursor including methyltrichlorosilane (MTS); a second densification including the formation of a second matrix phase by chemical vapor infiltration with a second SiC precursor different from the first precursor, the second precursor forming an SiC deposit comprising residual hydrogen and free silicon; and a third densification including the impregnation of the fibrous preform with an impregnation composition containing at least silicon so as to obtain a part made of SiC/SiC composite material.

Abstract: A core for producing a blade is formed by molding a fibrous preform around the core. The core extends in a longitudinal direction (L) between a root and a tip and has a first face and a second face connected to each other at a first longitudinal edge and at a second longitudinal edge. The core includes fluid passages formed in a transverse thickness of the core, these fluid passages being adapted to allow the passage of fluid from the first face to the second face and vice versa.

Abstract: A method including a step of forming a bond coating on a surface of a substrate, and a step of forming a barrier coating on the bond coating. The bond coating is formed by chemical vapor deposition, at a deposition temperature higher than 150° C., in particular 1200° C. or higher, of a precursor including silicon, and includes columnar grains of crystalline silicon.