A method includes depositing a porous silicon coat on a substrate to form a bulk phase of a bond coat and introducing a reactive gas into pores of the porous silicon coat. The reactive gas reacts with silicon adjacent the pores of the porous silicon coat to form a ceramic phase of the bond coat comprising a silicon-based ceramic and reduce porosity of the porous silicon coat. A temperature of the reactive gas is greater than about 1000° C.

A method of producing a melt infiltrated ceramic matrix composite (CMC) article that includes the steps of: forming a ceramic fiber preform; optionally, rigidizing the ceramic fiber preform with a fiber interphase coating via a Chemical Vapor Infiltration (CVI) process, infiltrating a ceramic slurry into the porous body or preform, conducting one or more secondary operations, and finally, melt infiltrating the preform with molten silicon or a silicon alloy to form the CMC article. The infiltration of a ceramic slurry into a ceramic fiber preform to form a green body is performed along with the use of convection and/or conduction as heat transfer mechanisms, such that the ceramic slurry does not require the incorporation of a pre-gelation material in order for the slurry to remain within the green body during subsequent processing steps.

A method of producing a CMC having a smooth surface includes forming a fiber preform; rigidizing the preform with an interphase coating; infiltrating a ceramic slurry into the preform to form a green body; conducting secondary operations on the green body; applying a slurry-based layer onto a portion of the green body; and infiltrating the green body with a molten silicon or silicon alloy, such that the CMC exhibits a smooth surface. The application of the slurry-based surface layer onto the green body includes placing the green body into a tool fixture having upper and lower components, such that a gap is present between the green body and at least one of the upper and lower components; and delivering a surface layer slurry into at least one gap, such that the surface layer slurry forms the slurry-based layer on at least a portion of the green body.

A method of producing a CMC having a smooth surface includes forming a fiber preform; rigidizing the preform with an interphase coating; infiltrating a ceramic slurry into the preform to form a green body; conducting secondary operations on the green body; applying a slurry-based layer onto a portion of the green body; and infiltrating the green body with a molten silicon or silicon alloy, such that the CMC exhibits a smooth surface. The application of the slurry-based surface layer onto the green body includes placing the green body into a tool fixture having upper and lower components, such that a gap is present between the green body and at least one of the upper and lower components; and delivering a surface layer slurry into at least one gap, such that the surface layer slurry forms the slurry-based layer on at least a portion of the green body.

The present invention discloses a high-strength prestressed composite ceramic and a preparation method thereof, and belongs to a ceramic reinforcing technology in the field of high-performance structural ceramics. Firstly, more than two kinds of bondable ceramics need to be determined to form a composite ceramic of a matrix material and a surface layer material, the matrix material should have sufficient strength and a higher expansion coefficient, and the surface layer material should have a lower expansion coefficient and a higher elastic modulus, realizing the balance of the surface layer compressive stress and the matrix tensile stress are formed after high-temperature co-sintering; and the surface layer compressive stress can greatly improve the bending strength of the composite ceramic. The magnitude of the compressive stress can be adjusted by optimizing the section ratio of the two materials of the cross sections, the surface prestress is designed to be more than the strength value of the surface layer material for the given two materials, and the section ratio is determined through deduction and calculation of a prestress calculation formula. The composite ceramic with prestress can be obtained after sintering greatly improving the strength. The present invention solves the current problem of difficulty in improving the strength of structural ceramics and has good practical value.

The present invention discloses a high-strength prestressed composite ceramic and a preparation method thereof, and belongs to a ceramic reinforcing technology in the field of high-performance structural ceramics. Firstly, more than two kinds of bondable ceramics need to be determined to form a composite ceramic of a matrix material and a surface layer material, the matrix material should have sufficient strength and a higher expansion coefficient, and the surface layer material should have a lower expansion coefficient and a higher elastic modulus, realizing the balance of the surface layer compressive stress and the matrix tensile stress are formed after high-temperature co-sintering; and the surface layer compressive stress can greatly improve the bending strength of the composite ceramic. The magnitude of the compressive stress can be adjusted by optimizing the section ratio of the two materials of the cross sections, the surface prestress is designed to be more than the strength value of the surface layer material for the given two materials, and the section ratio is determined through deduction and calculation of a prestress calculation formula. The composite ceramic with prestress can be obtained after sintering greatly improving the strength. The present invention solves the current problem of difficulty in improving the strength of structural ceramics and has good practical value.

Disclosed are devices and methods for semiconductor devices including a ceramic substrate. Aspects disclosed include semiconductor device including an electrical component, an alumina ceramic substrate and a substrate-film. The substrate-film is deposited on the alumina ceramic substrate. The substrate-film has a planar substrate-film surface opposite the alumina ceramic substrate. The electrical component is formed on the substrate-film surface of the substrate-film on the alumina ceramic substrate.

Disclosed are devices and methods for semiconductor devices including a ceramic substrate. Aspects disclosed include semiconductor device including an electrical component, an alumina ceramic substrate and a substrate-film. The substrate-film is deposited on the alumina ceramic substrate. The substrate-film has a planar substrate-film surface opposite the alumina ceramic substrate. The electrical component is formed on the substrate-film surface of the substrate-film on the alumina ceramic substrate.

A method of fabricating a coating includes providing a ceramic matrix composite that includes SiC fibers disposed in a SiC matrix, depositing a base slurry on the ceramic matrix composite, wherein the base slurry contains powders of a metal oxide, at least one of silicon carbide, silicon nitride, or free silicon, and barium-magnesium-aluminosilicate in a first carrier fluid, drying the deposited base slurry to produce a base green layer, depositing a transition slurry on the base green layer, wherein the transition slurry contains powders of a metal oxide, at least one of silicon carbide, silicon nitride, or free silicon, at least one of zirconium carbide, zirconium nitride, or zirconium oxide, and barium-magnesium-aluminosilicate in a second carrier fluid, drying the deposited transition slurry to produce a transition green layer, and forming a consolidated coating on the ceramic matrix composite by heating the base green layer and the at least one transition green layer to cause chemical reactions that convert the powders to metal-silicon-oxygen rich phase and metal-zirconium-oxygen rich phase.

A coated component, along with methods of making and using the same, is provided. The coated component includes a ceramic matrix composite (CMC) substrate comprising silicon carbide and having a surface; a mullite/NOSC bondcoat on the surface of the substrate; and an environmental barrier coating on the mullite/NOSC bondcoat. The mullite/NOSC bondcoat comprises a non-oxide silicon ceramic (NOSC) phase contained within a mullite phase, with the mullite/NOSC bondcoat comprising 60% to 95% by volume of the mullite phase, such as 65% to 93% by volume of the mullite phase.