The invention relates to SiC ceramic matrix composite (CMC) claddings with metallic, ceramic and/or multilayer coatings applied on the outer surface for improved corrosion resistance and hermeticity protection. The coating includes one or more materials selected from FeCrAl, Y, Zr and AlCr alloys, Cr.sub.2O.sub.3, ZrO.sub.2 and other oxides, chromium carbides, CrN, Zr- and Y-silicates and silicides. The coatings are applied employing a variety of known surface treatment technologies including cold spray, thermal spray process, physical vapor deposition process (PVD), and slurry coating.

The invention relates to SiC ceramic matrix composite (CMC) claddings with metallic, ceramic and/or multilayer coatings applied on the outer surface for improved corrosion resistance and hermeticity protection. The coating includes one or more materials selected from FeCrAl, Y, Zr and AlCr alloys, Cr.sub.2O.sub.3, ZrO.sub.2 and other oxides, chromium carbides, CrN, Zr- and Y-silicates and silicides. The coatings are applied employing a variety of known surface treatment technologies including cold spray, thermal spray process, physical vapor deposition process (PVD), and slurry coating.

Disclosed are a semi-transparent ceramic sheet decorated through ink light-absorbance and a preparation method thereof. The semi-transparent ceramic sheet comprises a semi-transparent green body, an inner inkjet pattern layer infiltrating into the semi-transparent green body from an upper surface of the semi-transparent green body, a decoloration glaze layer located on the upper surface, and a surface pattern layer located on the decoloration glaze layer. The decoloration glaze layer is capable of decoloring the ink of the inner inkjet pattern layer. The semi-transparent ceramic sheet is provided with the decoloration glaze layer so that the inkjet decoration of the inner inkjet pattern layer cannot be displayed on the surface, and the decorative pattern on the surface of the green body is the surface pattern layer and the inner inkjet pattern layer is completely in the inner layer of the green body.

Disclosed are a semi-transparent ceramic sheet decorated through ink light-absorbance and a preparation method thereof. The semi-transparent ceramic sheet comprises a semi-transparent green body, an inner inkjet pattern layer infiltrating into the semi-transparent green body from an upper surface of the semi-transparent green body, a decoloration glaze layer located on the upper surface, and a surface pattern layer located on the decoloration glaze layer. The decoloration glaze layer is capable of decoloring the ink of the inner inkjet pattern layer. The semi-transparent ceramic sheet is provided with the decoloration glaze layer so that the inkjet decoration of the inner inkjet pattern layer cannot be displayed on the surface, and the decorative pattern on the surface of the green body is the surface pattern layer and the inner inkjet pattern layer is completely in the inner layer of the green body.

A process for manufacturing a composite part includes introducing an adhesion promoter into the pores of a fibrous preform formed by threads covered with a coating having OH groups on its surface, the adhesion promoter including an electron-withdrawing group G1 that is reactive according to a reaction of substitution or of nucleophilic addition with the OH groups, and a reactive group G2; grafting the adhesion promoter to the surface of the coating by a reaction of substitution or nucleophilic addition of the OH groups on the group G1; introducing a ceramic precursor resin into the pores of the fibrous preform; polymerizing the resin introduced and bonding the grafted adhesion promoter to the resin by chemical reaction between these two compounds at the level of the group G2, and forming a ceramic matrix phase in the pores of the fibrous preform by pyrolysis of the polymerized resin.

Embodiments of the invention can be directed to controlling and/or engineering the size and/or volume of polar nanoregions (PNRs) of ferroelectric polycrystalline material systems. Some embodiments can achieved this via composition modifications to cause changes in the PNRs and/or local structure. Some embodiments can be used to control and/or engineer dielectric, piezoelectric, and/or electromechanical properties of polycrystalline materials. Controlling and/or engineering the PNRs may facilitate improvements to the dielectric, piezoelectric, and/or electromechanical properties of materials. Controlling and/or engineering the PNRs may further facilitate generating a piezoelectric material that may be useful for many different piezoelectric applications.

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.

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.

A method of depositing abradable coating on an engine component is provided wherein the engine component is formed of ceramic matrix composite and one or more layers, including at least one environmental barrier coating, may be disposed on the outer layer of the CMC. An outermost layer of the structure may further comprise a porous abradable layer that is disposed on the environmental barrier coating and provides a breakable structure which inhibits blade damage. The abradable layer may be gel-cast on the component and sintered or may be direct written by extrusion process and subsequently sintered.

A method of depositing abradable coating on an engine component is provided wherein the engine component is formed of ceramic matrix composite and one or more layers, including at least one environmental barrier coating, may be disposed on the outer layer of the CMC. An outermost layer of the structure may further comprise a porous abradable layer that is disposed on the environmental barrier coating and provides a breakable structure which inhibits blade damage. The abradable layer may be gel-cast on the component and sintered or may be direct written by extrusion process and subsequently sintered.