Methods of forming a ceramic matrix, as well as fiber preforms and methods of forming fiber preforms to facilitate formation of a ceramic matrix are provided. The method includes obtaining a fiber preform to facilitate forming the ceramic matrix. The fiber preform includes a fiber layer with a plurality of fibers and a heating element embedded within the fiber preform. The method also includes heating the fiber preform via the heating element embedded within the fiber preform, and depositing matrix material into the fiber preform by embedded wire chemical vapor deposition (EWCVD) of the matrix material during the heating of the fiber preform by the heating element. The chemical vapor deposition of the matrix material within the fiber preform facilitates formation of the ceramic matrix.

A seal includes a ceramic matrix composite ply having woven ceramic-based fibers in a ceramic-based matrix. The ceramic matrix composite ply has at least one bend formed about a bend axis and defines at least one rounded portion. A sealed assembly and a method of making a seal are also disclosed.

A method of forming a ceramic matrix composite with being impregnated with molten metal includes: stacking a plurality of fiber layers that are layers of reinforced fibers impregnated with base resin to form a laminate in which a matrix layer containing fibers extending in a direction of impregnation with the molten metal is disposed between the fiber layers; forming an impregnation path in the matrix layer entirely in an in-plane direction perpendicular to a direction of the stacking in the laminate by carbonizing the formed laminate; and impregnating, with the molten metal, the laminate in which the impregnation path has been formed.

An automated preparation method of a SiC.sub.f/SiC composite flame tube, comprising the following steps: preparing an interface layer for a SiC fiber by a chemical vapor infiltration process, and obtaining the SiC fiber with a continuous interface layer; laying a unidirectional tape on the SiC fiber with the continuous interface layer and winding the SiC fiber with the continuous interface layer to form and obtaining a preform of a net size molding according to a fiber volume and a fiber orientation obtained in a simulation calculation; and adopting a reactive melt infiltration process and the chemical vapor infiltration process successively for a densification and obtaining a high-density SiC.sub.f/SiC composite flame tube in a full intelligent way. The SiC.sub.f/SiC composite flame tube prepared by the present disclosure not only has a high temperature resistance, but also has a low thermal expansion coefficient, high thermal conductivity and high thermal shock resistance.

The method includes forming an inner monolithic layer from crystals of beta phase stoichiometric silicon carbide on a carbon substrate in the form of a rod by chemical methylsilane vapor deposition in a sealed tubular hot-wall CVD reactor. The method further includes forming a central composite layer over the inner monolithic layer by twisting continuous beta phase stoichiometric silicon carbide fibers into tows, transporting the tows to a braiding machine, and forming a reinforcing thread framework. A pyrocarbon interface coating is built up by chemical methane vapor deposition in a sealed tubular hot-wall CVD reactor. Then, a matrix is formed by chemical methylsilane vapor deposition in the reactor. A protective outer monolithic layer is formed from crystals of beta phase stoichiometric silicon carbide over the central composite layer by chemical methylsilane vapor deposition in a CVD reactor. And then the carbon substrate is removed from the fabricated semi-finished product.

A mandrel for a molding process includes a first portion and a second portion that form a mandrel having a channel between the first and second portions. At least one locking pin is configured to urge the first and second portions away from each other to establish a gap in response to inserting the locking pin into the channel along a respective end of the mandrel. A molding apparatus and method of forming a matrix composite component are also disclosed.

A seal includes a ceramic matrix composite ply having woven ceramic-based fibers in a ceramic-based matrix. The ceramic matrix composite ply has at least one bend formed about a bend axis and defines at least one rounded portion. A sealed assembly and a method of making a seal are also disclosed.

A method of forming a ceramic matrix composite component. The ceramic matrix composite component is adapted for use in a gas turbine engine. The method including forming the component using ceramic materials and infiltrating the component with a matrix material.

A method for constructing multiple ceramic layers by winding continuous ceramic filaments of different compositions to prepare multilayer RF-transparent structures is provided. In the method, different continuous ceramic filaments are braided to construct layers with specific dielectric constants and braiding count/thickness. Layers with same or different dielectric characteristics forms a sandwich design to fulfill the desired mechanical, thermal and electrical requirements.

A method for forming a high temperature coating includes forming a pre-sintered ceramic coating on a ceramic composite substrate. The pre-sintered ceramic coating includes a plurality of ceramic particles. The method further includes sintering at least a portion of the pre-sintered ceramic coating by heating the portion of the pre-sintered ceramic coating to a sintering temperature of the plurality of ceramic particles using joule heating. The sintering temperature is greater than about 1000 degrees Celsius (° C.).