A method for manufacturing ceramic matrix composites (CMC) and CMCs made by the method are disclosed. The method can be a manual process or an automated process, such as using a robotic system, that is used for controlled delivery of ceramic particles in a CMC fabric. The method includes identifying voids present between adjacent tows of the CMC fabric and dispensing ceramic particles into the voids. Applying the ceramic particles in the center of the voids reduces the size and volume fraction of the voids/defects, improving the homogeneity of surface texture of the preform, homogeneity of microstructure, and part model shape conformity. The method for manufacturing CMCs creates CMCs having a homogenous distribution of small pores after matrix formation that improves the interlaminar mechanical and thermal properties of the CMCs.

According to an aspect of the invention, there is provided a plasma-resistant member including: a base member; and a layer structural component formed at a surface of the base member, the layer structural component including an yttria polycrystalline body and being plasma resistant, the layer structural component including a first uneven structure, and a second uneven structure formed to be superimposed onto the first uneven structure, the second uneven structure having an unevenness finer than an unevenness of the first uneven structure.

In one example, a method for forming an environmental barrier coating (EBC) and/or abradable coating on a substrate. The method may include depositing a coating on a ceramic or ceramic matrix composite (CMC) substrate to form an as-deposited coating, wherein the coating includes at least one of an environmental barrier coating (EBC) and an abradable coating. The method further comprises heat treating the as-deposited coating at or above a first temperature for a first period of time following the deposition of the as-deposited coating on the substrate, wherein heat treating the as-deposited coating includes heating the as-deposited coating to or above the first temperature at a controlled rate. The heat treatment may be configured to at least one of decrease the open pores and/or microcracks of the heat-treated coating compared to the as-deposited coating or control a grain size of the heat-treated coating.

Disclosed are an organic binder-based coating; a composite gypsum board containing face and back cover sheets, an outside surface of the back cover sheet bearing the coating; and a method of preparing composite board where the back cover sheet contains the coating on its outer surface. The coating is formed from a composition comprising an alkaline silicate, a solid filler, and optionally, a borate. An enhancing layer can also be applied to the back cover sheet.

Systems and methods for forming an oxidation protection system on a composite structure are provided. In various embodiments, the oxidation protection system comprises a boron-glass layer formed on the composite substrate and a silicon-glass layer formed over the boron-glass layer. Each of the boron-glass layer and the silicon-glass layer includes a glass former.

A gas turbine engine article includes a substrate and a silicate-resistant barrier coating disposed on the substrate. The silicate-resistant barrier coating is composed of a refractory matrix and a calcium aluminosilicate additive (CAS additive) dispersed in the refractory matrix.

A method to produce a ceramic matrix composite with controlled surface characteristics includes: applying a scrim ply to a surface of a fiber preform, where the fiber preform includes silicon carbide fibers coated with boron nitride; infiltrating the fiber preform and the scrim ply with a slurry, thereby forming an impregnated ply on an impregnated fiber preform; infiltrating the impregnated fiber preform and the impregnated ply with a melt comprising silicon, and then cooling, thereby forming a ceramic matrix composite having a ceramic surface layer thereon, where the ceramic surface layer has a predetermined thickness and is devoid of boron; machining or grit blasting the ceramic surface layer to form an intermediate layer suitable for coating; and depositing an environmental barrier coating on the intermediate layer. Thus, a ceramic matrix composite coated with the environmental barrier coating is formed with the intermediate layer in between.

A method for coating a ceramic matrix composite substrate with an environmental barrier coating includes the steps of: treating a surface of a ceramic matrix composite substrate to adjust wettability of the surface; and applying an aqueous slurry-based environmental barrier coating to the surface. The treating step can be a plasma treatment to remove organic contaminants, and can also be a treatment to modify oxidative state of the surface. The treatment can produce a surface for treatment that is hydrophilic and has a contact angle with aqueous-slurry coating materials of less than 40 degrees.

A method for coating a ceramic matrix composite substrate with an environmental barrier coating includes the steps of: treating a surface of a ceramic matrix composite substrate to adjust wettability of the surface; and applying an aqueous slurry-based environmental barrier coating to the surface. The treating step can be a plasma treatment to remove organic contaminants, and can also be a treatment to modify oxidative state of the surface. The treatment can produce a surface for treatment that is hydrophilic and has a contact angle with aqueous-slurry coating materials of less than 40 degrees.

An oxidation protection system disposed on a substrate is provided, which may comprise a boron layer comprising a boron compound disposed on the substrate; a silicon layer comprising a silicon compound disposed on the boron layer; and at least one sealing layer comprising monoaluminum phosphate and phosphoric acid disposed on the silicon layer.