A thermal protection system is provided for a vehicle substructure. The thermal protection system comprises an outer layer for protecting the vehicle substructure. The thermal protection system further comprises an inner layer for conforming to the vehicle substructure. The thermal protection system also comprises an insulation layer sandwiched between the inner and outer layers. The insulation layer includes a porous low-density ceramic insulating material having a densified portion that covers an inner surface of the outer layer to strengthen adhesion.

Systems, structures, devices, and fabrication processes for ceramic matrix composites suitable for use in a nuclear reactor environment and other applications requiring materials that can withstand high temperatures and/or highly corrosive environments are disclosed. In one aspect, a ceramic composite structure is provided. The structure comprises a chamber including an external shell and a hollow space inside the external shell. The external shell includes an inner composite layer including a first composite structure, a middle composite layer placed outside of the inner composite layer, the middle composite layer including a second composite structure that is different from the first composite structure, and an outer monolithic layer that has a spatially uniform material property and placed outside of the middle composite layer.

A method of forming an integral fastener for a ceramic matrix composite component comprises the steps of forming a fiber preform with an opening, forming a fiber fastener, inserting the fiber fastener into the opening, and infiltrating a matrix material into the fiber preform and fiber fastener to form a ceramic matrix composite component with an integral fastener. A gas turbine engine is also disclosed.

A preform CMC article is disclosed comprising an interior ply structure having at least one interior CMC ply including at least one longitudinal CMC ply disposed along the article length, an exterior shell ply forming an article surface and having at least one exterior CMC ply substantially surrounding the interior ply structure, and at least one wicking portion in which the interior ply structure penetrates the exterior ply shell with an exposed edge of the longitudinal CMC ply disposed at the article surface. A CMC article is disclosed including the interior ply structure and the exterior ply shell, wherein the longitudinal CMC ply includes an exposed edge disposed at the surface of the CMC article. A method for forming the CMC article is disclosed including wicking a melt infiltration agent into the article through the wicking portion into the interior ply structure along the longitudinal CMC ply.

A cementitious composition includes (i) white Portland cement having a fineness of about 350-550 m.sup.2/kg, D90 between about 11-50 m, and total combined iron oxide, manganese oxide, and chromium oxide <1.0% by weight (ii) light color pozzolan such as white silica fume, and (iii) at least one light color particulate material, such as ground granulated blast furnace slag (GGBFS) having a fineness greater than that of the white Portland cement, a D90 less than that of the white Portland cement, and total combined iron oxide, manganese oxide, and chromium oxide content <3.0% by weight and/or coarse limestone powder having a D90 greater than that of the white cement. The cementitious composition may include one or more of aggregates, fibers, or admixture. The cementitious composition can be a dry blend, fresh cementitious mixture, or hardened cementitious composition. The cementitious composition can be precast concrete, stucco, GFRC, UHPC or SCC.

The disclosure describes techniques for forming a surface layer of an article including a CMC using a cast. In some examples, the surface layer includes three-dimensional surface features, which may increase adhesion between the CMC and a coating on the CMC. In some examples, the surface layer may include excess material, with or without three-dimensional surface features, which is on the CMC. The excess material may be machined to remove some of the excess material and facilitate conforming the article to dimensional tolerances, e.g., for fitting the article to another component. The excess material may reduce a likelihood that the CMC (e.g., reinforcement material in the CMC) is damaged by the machining.

An article includes a ceramic wall that defines at least a side of a passage. The ceramic wall includes a flow turbulator that projects into the passage. The flow turbulator is formed of ceramic matrix composite.

The present disclosure is related to turbine wheel assemblies for gas turbine engines. Such turbine wheel assemblies may include ceramic matrix composite airfoil components mounted with different types of coupling to a central disc.

The present invention relates to a heat-permeable tube which has a double-walled construction. The material of the interior wall contains ceramic matrix composite. The material of the exterior wall contains metal. The present invention further relates to the use of this tube in a rotary tube furnace and the use of the rotary tube furnace for thermal treatment of materials. Furthermore, the invention relates to the use of a single-walled tube containing ceramic matrix composite as rotary tube.

A method includes providing a ceramic insert on a mandrel, the mandrel and the ceramic insert together define a peripheral working surface, forming a fiber preform by wrapping a fiber layer around the mandrel and the ceramic insert so as to conform to the peripheral working surface, removing the mandrel from the fiber preform to leave a cavity in the fiber preform, the ceramic insert remaining in the fiber preform and bordering the cavity, and densifying the fiber preform with a ceramic matrix to form a gas turbine engine component.