Patent classifications
C04B2235/614
Mitigating pyrophoric deposits in exhaust piping during SIC CVI/CVD processes by introducing water vapor into an outlet portion of a reaction chamber
Systems for and methods of manufacturing a ceramic matrix composite include introducing a gaseous precursor into an inlet portion of a reaction furnace having a chamber comprising the inlet portion and an outlet portion that is downstream of the inlet portion, and delivering a mitigation agent, such as water vapor or ammonia, into an exhaust conduit in fluid communication with and downstream of the outlet portion of the reaction chamber so as to control chemical reactions occurring with the exhaust chamber. Introducing the gaseous precursor densities a porous preform, and introducing the mitigation agent shifts the reaction equilibrium to disfavor the formation of harmful and/or pyrophoric byproduct deposits within the exhaust conduit.
BIFURACTING LAYUP FOR AIRFOIL RIB, METHODS OF MANUFACTURE THEREOF AND ARTICLES COMPRISING THE SAME
An airfoil comprises a wall that defines a leading edge and a trailing edge and one or more cavities located within the wall along with a rib that separates the cavities. The rib or the wall comprises a first split ply that comprises a consolidated section and two or more split sections; wherein the split sections emanate from the consolidated section; and where the split sections define the wall and the cavities of the airfoil.
SYSTEM AND METHOD FOR ENHANCING A DIFFUSION LIMITED CVI/CVD PROCESS
A system and method for enhancing a diffusion limited CVI/CVD process is provided. The system may densify a porous structure by flowing a reactant gas around the porous structure. A mass flow controller may be configured to pulse the flow rate of the reactant gas around the porous structure. The mass flow controller may pulse the flow rate from a nominal flow rate to a first flow rate. The mass flow controller may pulse the first flow rate back to the nominal flow rate or to a second flow rate. The mass flow controller may pulse the flow rate between the nominal flow rate, the first flow rate, and the second flow rate, as desired.
SYSTEMS AND METHODS FOR CARBON STRUCTURES INCORPORATING SILICON CARBIDE WHISKERS
A method of treating a carbon structure is provided. The method may include infiltrating the carbon structure with a silicon compound preparation, heat treating the carbon structure to form a plurality of silicon carbide whiskers in the carbon structure, and/or densifying the carbon structure.
FAST-DENSIFIED CERAMIC MATRIX COMPOSITE AND FABRICATION METHOD
A method for producing a ceramic matrix composite (CMC) material includes impregnating a set of ceramic fibers with a non-fibrous ceramic material, resulting in a precursor matrix, stabilizing the precursor matrix, resulting in a stabilized matrix, and densifying the stabilized matrix using a frequency assisted sintering technology (FAST) process, resulting in a densified CMC material. The resulting densified CMC exhibits superior strength and toughness, relative to prior CMCs.
Flexible ceramic matrix composite seal
A ceramic matrix composite seal is disclosed. The ceramic matrix composite seal including a ceramic matrix and a number of ceramic fiber fabrics embedded in the ceramic matrix. The ceramic matrix composite seal is formed into a strip with a desired geometry such that the seal strip is configured to be assembled with a number of components to create a seal between the components.
CHEMICAL VAPOUR INFILTRATION OR DEPOSITION PROCESS
A process for chemical vapor infiltration or deposition, includes forming pyrocarbon in the porosity of a porous substrate or on a surface of a substrate, the substrate being placed in a reaction chamber and the pyrocarbon being formed from a gas phase introduced into the reaction chamber, the gas phase including at least one pyrocarbon precursor compound and carbon dioxide.
Systems and methods for producing a carbon composite material
A carbon/carbon brake disk is provided. The carbon/carbon brake disk may comprise a carbon fiber, wherein the carbon fiber is formed into a fibrous network, wherein the fibrous network comprises carbon deposited therein. The carbon fiber may undergo a FHT process, wherein micro-cracks are disposed in the carbon fiber. In various embodiments, the micro-cracks may be at least partially filled with un-heat-treated carbon via a final CVD process, wherein the final CVD process is performed at a temperature in the range of up to about 1,000° C. (1,832° F.) for a duration in the range from about 20 hours to about 100 hours. In various embodiments, the un-heat-treated carbon may be configured to prevent oxygen, moisture, and/or oxidation protection systems (OPS) chemicals from penetrating the carbon/carbon brake disk. In various embodiments, the final CVI/CVD process may be configured to increase the wear life of the carbon/carbon brake disk.
Method of chemical vapor infiltration or deposition
A method of chemical vapor infiltration or deposition includes forming silicon carbide in pores of a porous substrate or on a surface of a substrate, the substrate being placed in a reaction enclosure, the silicon carbide being formed from a gas phase introduced into the reaction enclosure, the gas phase including a reagent compound that is a precursor of silicon carbide and that has the following formula ##STR00001##
in which n is an integer equal to 0 or 1; m is an integer lying in the range 1 to 3; p is an integer lying in the range 0 to 2 with m+p=3; and R designates —H or —CH.sub.3; a ratio C/Si between the number of carbon atoms and the number of silicon atoms in the introduced gas phase lying in the range 2 to 3.
Surface layer on a ceramic matrix composite
The disclosure describes a method for forming a surface layer of a ceramic matrix composite (CMC) article. The technique includes depositing a slurry on a surface of an infiltrated CMC. The slurry includes a carrier material, a binder, a plasticizer, and solid particles. The solid particles include a plurality of fine ceramic particles defining a fine particle average size less than about 5 micrometers. The method further includes drying the slurry to form an article having an outer surface layer that includes the solid particles on the infiltrated CMC. The method further includes machining at least a portion of the outer surface layer of the article. The method further includes infiltrating the article with a molten infiltrant to form a composite article.