Provided are stacks including CMC structures and capping layers deposited on surfaces of these CMC structures. Also provided are methods for hermetically sealing the surfaces of the CMC structures with the capping layers. These stacks may be used to construct walls of radomes that enclose antennas and other equipment of aerospace vehicles. The capping layers may form smooth external surfaces of the radomes and may hermetically seal the underlying CMC structures. The dielectric properties of these stacks may be configured to minimize interference with operations of the antennas and other equipment deposited within the radome.

Provided are stacks including CMC structures and capping layers deposited on surfaces of these CMC structures. Also provided are methods for hermetically sealing the surfaces of the CMC structures with the capping layers. These stacks may be used to construct walls of radomes that enclose antennas and other equipment of aerospace vehicles. The capping layers may form smooth external surfaces of the radomes and may hermetically seal the underlying CMC structures. The dielectric properties of these stacks may be configured to minimize interference with operations of the antennas and other equipment deposited within the radome.

A method includes a slurry preparing process of preparing a ceramic powder slurry, an impregnating process of impregnating the slurry into an inorganic fiber sheet to form an impregnated sheet, a sheet winding process of winding an impregnated sheet around a core to form a sheet-wound core, a pressing process of disposing the impregnated sheet between a first mold and a second mold opposed to each other and interposing a spacer therebetween at a portion where the impregnated sheet is not positioned, and then clamping the first mold and the second mold with a first fastener to come close in a direction facing each other, thereby applying pressure to the impregnated sheet, a drying process of heating and drying the impregnated sheet, and a firing process of firing the sheet after drying.

A method includes a slurry preparing process of preparing a ceramic powder slurry, an impregnating process of impregnating the slurry into an inorganic fiber sheet to form an impregnated sheet, a sheet winding process of winding an impregnated sheet around a core to form a sheet-wound core, a pressing process of disposing the impregnated sheet between a first mold and a second mold opposed to each other and interposing a spacer therebetween at a portion where the impregnated sheet is not positioned, and then clamping the first mold and the second mold with a first fastener to come close in a direction facing each other, thereby applying pressure to the impregnated sheet, a drying process of heating and drying the impregnated sheet, and a firing process of firing the sheet after drying.

A ceramic component is generally provided that includes a silicon-based layer comprising a silicon-containing material (e.g., a silicon metal and/or a silicide) and about 0.001% to about 85% of an In-containing compound. For example, the silicon-based layer can be a bond coating directly on the surface of the substrate. Alternatively or additionally, the silicon-based layer can be an outer layer defining a surface of the substrate, with an environmental barrier coating on the surface of the substrate. Gas turbine engines are also generally provided that include such a ceramic component.

A ceramic component is generally provided that includes a silicon-based layer comprising a silicon-containing material (e.g., a silicon metal and/or a silicide) and about 0.001% to about 85% of an In-containing compound. For example, the silicon-based layer can be a bond coating directly on the surface of the substrate. Alternatively or additionally, the silicon-based layer can be an outer layer defining a surface of the substrate, with an environmental barrier coating on the surface of the substrate. Gas turbine engines are also generally provided that include such a ceramic component.

Provided are methods for hermetically sealing the surfaces of the CMC structures with the capping layers, comprising depositing a slurry onto the surface of a CMC structure and treating the CMC structure with the deposited slurry in an oxygen containing environment, thereby forming a stack. These stacks may be used to construct walls of radomes that enclose antennas and other equipment of aerospace vehicles. The capping layers may form smooth external surfaces of the radomes and may hermetically seal the underlying CMC structures. The dielectric properties of these stacks may be configured to minimize interference with operations of the antennas and other equipment deposited within the radome.

Provided are methods for hermetically sealing the surfaces of the CMC structures with the capping layers, comprising depositing a slurry onto the surface of a CMC structure and treating the CMC structure with the deposited slurry in an oxygen containing environment, thereby forming a stack. These stacks may be used to construct walls of radomes that enclose antennas and other equipment of aerospace vehicles. The capping layers may form smooth external surfaces of the radomes and may hermetically seal the underlying CMC structures. The dielectric properties of these stacks may be configured to minimize interference with operations of the antennas and other equipment deposited within the radome.

An apparatus includes a ceramic matrix composite (CMC) component and an interface coating on the CMC component, wherein the interface coating includes a layer of at least one of the following compositions: 40-50 wt % Nb, 28-42 wt % Al, 4-15 wt % Cr, 1-2 wt % Si; 90-92 wt % Mo, 4-5 wt % Si, 4-5 wt % B; or 60-80 wt % V, 20-30 wt % Cr, 2-15 wt % Ti.

An apparatus includes a ceramic matrix composite (CMC) component and an interface coating on the CMC component, wherein the interface coating includes a layer of at least one of the following compositions: 40-50 wt % Nb, 28-42 wt % Al, 4-15 wt % Cr, 1-2 wt % Si; 90-92 wt % Mo, 4-5 wt % Si, 4-5 wt % B; or 60-80 wt % V, 20-30 wt % Cr, 2-15 wt % Ti.