A cathode having a tandem electrocatalyst structure is provided. The cathode includes a plurality of wires spaced apart from each other, a layer formed on a surface of each of the plurality of wires, and a plurality of nanoparticles disposed on the layer. Each of the plurality of wires includes a first perovskite material or a metal. The layer includes a second perovskite material. Each of the nanoparticles includes a metal oxide.

There is disclosed herein processes and systems for forming fiber-reinforced ceramic composite structures which, contrary to conventional methods, directly deposit a ceramic fiber composite on a working surface. The processes and systems enable the printing of ceramic fiber composite structures having complex shapes and allow for multiple fiber-matrix material combinationsso far not possible with conventional approaches. In addition, the systems and process described herein enable the printing of ceramic fiber composites on complex 3D surfaces, such as gas turbine components.

A ceramic bonding material including at least one fibrous material, a flux agent and a thickening agent wherein the ceramic bonding material fired at a set temperature to bond the two adjacent substrate faces.

A process for producing a molded insulating part, a molded insulating part and a casting tool for the production of an inorganic pulp composed of water, glass fibers and/or mineral fibers and sheet silicate, introduction of the pulp into a cavity of a casting tool whose wall is at least partially water-permeable, which cavity has on at least one side the negative shape of the molded insulating part to be produced, removal of the aqueous fraction present in the pulp, opening of the casting tool and subsequent taking-out of the molded insulating part produced. The pulp produced using water for producing the molded insulating part comprised a glass fiber/sheet silicate mixture or mineral fiber/sheet silicate mixture has a proportion of exclusively synthetic sheet silicate (5) in the range from 0.5% to 2.5% and a proportion of glass fibers and/or mineral fibers (4) of from 0.3 to 1.5%.

A method of producing a ceramic matrix composite material component is provided. The method includes that steps of: a) producing a preform having one or more ceramic constituents, the preform being porous with internal voids; and b) applying at least one layer of a first material to the preform using an atomic layer deposition (ALD) process to decrease a porosity of the preform.

A ceramic bonding material including at least one fibrous material, a flux agent and a thickening agent wherein the ceramic bonding material fired at a set temperature to bond the two adjacent substrate faces.

Some variations provide a process for fabricating a ceramic structure, the process comprising: producing a plurality of preceramic polymer parts; chemically, physically, and/or thermally joining the preceramic polymer parts together, to generate a preceramic polymer structure; thermally treating the preceramic polymer structure, to generate a ceramic structure; and recovering the ceramic structure. The process may employ additive manufacturing, subtractive manufacturing, casting, or a combination thereof. A composite overwrap may be applied to the preceramic polymer structure prior to pyrolysis, and the composite overwrap also pyrolyzes to a ceramic composite and is a part of the final ceramic structure. The ceramic structure may be silicon oxycarbide, silicon carbide, silicon nitride, silicon oxynitride, silicon carbonitride, silicon boronitride, silicon boron carbonitride, or boron nitride, for example. The ceramic structure may have at least one dimension of 1 meter or greater, and may be a fully integrated ceramic object with no seams.

A piezoelectric composite material includes a cross-linker and a plurality of ceramic fibers disposed in the cross-linker. The ceramic fibers include ABO.sub.3 oxide. A-site represents Pb.sub.xLa.sub.y containing lead (Pb) and lanthanum (La). In Pb.sub.xLa.sub.y, x ranges from 0.920 to 0.950, and y ranges from 0.050 to 0.080.

A ceramic article includes a ceramic matrix composite that has a porous reinforcement structure and a ceramic matrix within pores of the porous reinforcement structure. The ceramic matrix composite includes a surface zone comprised of an exterior surface of the ceramic matrix composite and pores that extend from the exterior surface into the ceramic matrix composite. A glaze material seals the surface zone within the pores of the surface zone and on the exterior surface of the surface zone as an exterior glaze layer on the ceramic matrix composite. The glaze material is a glass or glass-ceramic material. The ceramic matrix composite includes an interior zone under the surface zone, and the interior zone is free of any of the glaze material and has a greater porosity than the surface zone.

A method of forming an integral fastener for a ceramic matrix composite component comprises the steps of forming a fiber preform with an opening, forming a fiber fastener, inserting the fiber fastener into the opening, and infiltrating a matrix material into the fiber preform and fiber fastener to form a ceramic matrix composite component with an integral fastener. A gas turbine engine is also disclosed.