The present disclosure provides a method for coating a composite structure, comprising forming a first slurry by combining a first pre-slurry composition with a first carrier fluid, applying the first slurry on a surface of the composite structure, and heating the composite structure to a temperature sufficient to form a base layer on the composite structure. The first pre-slurry composition may comprise a first phosphate glass composition and a low coefficient of thermal expansion material, wherein the low coefficient of thermal expansion material is a material with a coefficient of thermal expansion of less than 10×10.sup.−6° C..sup.−1.

The present disclosure provides a method for coating a composite structure, comprising forming a first slurry by combining a first pre-slurry composition with a first carrier fluid, applying the first slurry on a surface of the composite structure, and heating the composite structure to a temperature sufficient to form a base layer on the composite structure. The first pre-slurry composition may comprise a first phosphate glass composition and a low coefficient of thermal expansion material, wherein the low coefficient of thermal expansion material is a material with a coefficient of thermal expansion of less than 10×10.sup.−6° C..sup.−1.

The present disclosure provides a method for coating a composite structure, comprising applying a first slurry on a surface of the composite structure, heating the composite structure to a temperature sufficient to form a base layer on the composite structure, forming a sealing slurry comprising at least one of acid aluminum phosphate or orthophosphoric acid, applying the sealing slurry to the base layer, and heating the composite structure to a second temperature sufficient to form a sealing layer on the base layer.

The present disclosure provides a method for coating a composite structure, comprising applying a first slurry on a surface of the composite structure, heating the composite structure to a temperature sufficient to form a base layer on the composite structure, forming a sealing slurry comprising at least one of acid aluminum phosphate or orthophosphoric acid, applying the sealing slurry to the base layer, and heating the composite structure to a second temperature sufficient to form a sealing layer on the base layer.

A method for densifying one or more porous substrates with pyrolytic carbon by chemical vapour infiltration, includes admitting, at the inlet of the densification furnace, a reactive gaseous phase including at least one pyrolytic carbon precursor; reacting at least a fraction of the reactive gaseous phase with the porous substrate or substrates; extracting, at the outlet of the densification furnace, gaseous effluents originating from the reactive gaseous phase; reintroducing, with the reactive gaseous phase admitted at the inlet of the densification furnace, at least a fraction of the gaseous effluents extracted at the outlet of the furnace, wherein the fraction of the gaseous effluents introduced with the reactive gaseous phase includes at least one polyaromatic hydrocarbon compound.

A method for densifying one or more porous substrates with pyrolytic carbon by chemical vapour infiltration, includes admitting, at the inlet of the densification furnace, a reactive gaseous phase including at least one pyrolytic carbon precursor; reacting at least a fraction of the reactive gaseous phase with the porous substrate or substrates; extracting, at the outlet of the densification furnace, gaseous effluents originating from the reactive gaseous phase; reintroducing, with the reactive gaseous phase admitted at the inlet of the densification furnace, at least a fraction of the gaseous effluents extracted at the outlet of the furnace, wherein the fraction of the gaseous effluents introduced with the reactive gaseous phase includes at least one polyaromatic hydrocarbon compound.

A loader device is arranged for densifying porous preforms of stackable shape by means of directed stream chemical vapor infiltration in a reaction chamber of an infiltration oven. The device comprises a support tray, a first stack having a plurality of bottom rings arranged on the support tray and a plurality of injection orifices, a second stack comprising a plurality of top rings and a plurality of discharge orifices extending between the outer periphery and inner periphery of each ring. The device includes a first non-porous wall corresponding to the porous preforms and arranged on the support tray inside the bottom rings of the first stack, and a second non-porous wall corresponding to the porous preforms extending between the bottom ring situated at the top of the first stack and the top ring situated at the top of the second stack.

A loader device is arranged for densifying porous preforms of stackable shape by means of directed stream chemical vapor infiltration in a reaction chamber of an infiltration oven. The device comprises a support tray, a first stack having a plurality of bottom rings arranged on the support tray and a plurality of injection orifices, a second stack comprising a plurality of top rings and a plurality of discharge orifices extending between the outer periphery and inner periphery of each ring. The device includes a first non-porous wall corresponding to the porous preforms and arranged on the support tray inside the bottom rings of the first stack, and a second non-porous wall corresponding to the porous preforms extending between the bottom ring situated at the top of the first stack and the top ring situated at the top of the second stack.

A method of fabricating a part out of composite material, includes forming a fiber texture from refractory fibers; impregnating the fiber texture for a first time with a first slip containing first refractory particles; eliminating the liquid phase from the first slip so as to leave within the texture only the first refractory particles; impregnating the fiber texture for a second time with a second slip containing second refractory particles; eliminating the liquid phase from the second slip so as to leave within the texture only the second refractory particles and obtain a fiber preform filled with the first and second refractory particles; and sintering the first and second refractory particles present in the fiber preform in order to form a refractory matrix in the preform.

Disclosed herein is a composite comprising a ceramic matrix composite comprising a ceramic matrix and ceramic fibers; and one or more sacrificial fibers woven into the ceramic matrix composite; where the sacrificial fibers are operative to undergo oxidation or melting upon being subjected to an elevated temperature; and wherein the sacrificial fibers leave cooling holes in the composite preform upon being subjected to oxidation or melting.