An environmental barrier coating, comprising a substrate containing silicon; an environmental barrier layer applied to said substrate; said environmental barrier layer comprising a rare earth composition.

An environmental barrier coating, comprising a substrate containing silicon; an environmental barrier layer applied to said substrate; said environmental barrier layer comprising a rare earth composition.

A method for fabricating multi-layer ceramic broadband radome includes thermal-spraying layers of coating materials on the radome. The assembled structure exhibits tuned RF transparency response depending on the thickness and the dielectric constant of the deposited layers. Sub-micron thick ceramic layers, which are essential for broadband performance and hard to produce due to their fragile nature, can be deposited on big and complex objects by a fast and automated process.

A method for fabricating multi-layer ceramic broadband radome includes thermal-spraying layers of coating materials on the radome. The assembled structure exhibits tuned RF transparency response depending on the thickness and the dielectric constant of the deposited layers. Sub-micron thick ceramic layers, which are essential for broadband performance and hard to produce due to their fragile nature, can be deposited on big and complex objects by a fast and automated process.

This technology relates to refractory coatings used in metal casting by the foundry industry. Refractory coatings are often used to coat foundry cores and molds for the purpose of improving the quality of castings formed in connection with the cores or molds, particularly at the surface of the casting. Whereas traditional coatings comprise water based solvents that require excessive drying times or HAPs that emit hazardous VOCs, preferred embodiments of the present invention comprise refractory coatings having VOC-exempt ester based solvents, such as DMC. Other preferred embodiments of the present invention comprise methods for reduction of VOC content in a foundry article.

An article for high temperature service is presented herein. One embodiment is an article including a substrate having a silicon-bearing ceramic matrix composite; and a layer disposed over the substrate, wherein the layer includes silicon and a dopant, the dopant including aluminum. In another embodiment, the article includes a ceramic matrix composite substrate, wherein the composite includes a silicon-bearing ceramic and a dopant, the dopant including aluminum; a bond coat disposed over the substrate, where the bond coat includes elemental silicon, a silicon alloy, a silicide, or combinations including any of the aforementioned; and a coating disposed over the bond coat, the coating including a silicate (such as an aluminosilicate or rare earth silicate), yttria-stabilized zirconia, or a combination including any of the aforementioned.

An article for high temperature service is presented herein. One embodiment is an article including a substrate having a silicon-bearing ceramic matrix composite; and a layer disposed over the substrate, wherein the layer includes silicon and a dopant, the dopant including aluminum. In another embodiment, the article includes a ceramic matrix composite substrate, wherein the composite includes a silicon-bearing ceramic and a dopant, the dopant including aluminum; a bond coat disposed over the substrate, where the bond coat includes elemental silicon, a silicon alloy, a silicide, or combinations including any of the aforementioned; and a coating disposed over the bond coat, the coating including a silicate (such as an aluminosilicate or rare earth silicate), yttria-stabilized zirconia, or a combination including any of the aforementioned.

A coating method includes depositing a slurry including a coarsely particulate ceramic and a finely particulate ceramic on a base material configured with an oxide-based ceramics matrix composite such that a proportion of coarse particles decreases towards a surface of the base material; forming a bond coating by performing a heat treatment on the base material on which the slurry has been deposited; and forming a top coating by thermally spraying a ceramic onto the bond coating. The oxide-based ceramics matrix composite is an alumina silica type oxide-based ceramics matrix composite. The coarsely particulate ceramic and the finely particulate ceramic are alumina-based powder.

A coating method includes depositing a slurry including a coarsely particulate ceramic and a finely particulate ceramic on a base material configured with an oxide-based ceramics matrix composite such that a proportion of coarse particles decreases towards a surface of the base material; forming a bond coating by performing a heat treatment on the base material on which the slurry has been deposited; and forming a top coating by thermally spraying a ceramic onto the bond coating. The oxide-based ceramics matrix composite is an alumina silica type oxide-based ceramics matrix composite. The coarsely particulate ceramic and the finely particulate ceramic are alumina-based powder.

A coated component, along with methods of its formation and use, is provided. The coated component includes a ceramic matrix composite (CMC) substrate comprising silicon carbide and having a mullite bondcoat on its surface. The mullite bondcoat includes an oxygen getter phase contained within a mullite phase. For example, the mullite bondcoat may include 60% to 98% by volume of the mullite phase. An environmental barrier coating is on the mullite bondcoat.