This patent document relates to systems, structures, devices, and fabrication processes for ceramic matrix composites suitable for use in a nuclear reactor environment and other applications requiring materials that can withstand high temperatures and/or highly corrosive environments. In one exemplary aspect, a method of joining and sealing ceramic structures is disclosed. The method comprises forming a joint of a ceramic structure and an end plug using a sealing material, wherein the end plug has a hole that goes through a top surface and a bottom surface of the end plug; filling the ceramic structure with a desired gas composition through the hole; heating a material into a molten form using a heat source; and directing the material into the hole, wherein the material solidifies to seal the end plug.

A direct bonded copper ceramic substrate is provided, which includes a nitride ceramic substrate, a first passivation layer, and a first copper layer. The first passivation layer includes aluminum oxide or silicon oxide doped with another metal. The other metal is titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, or a combination thereof. The aluminum or silicon and the other metal have a weight ratio of 60:40 to 99.5:0.5. The first passivation layer is disposed between the top surface of the nitride ceramic substrate and the first copper layer.

Methods of forming ceramic matrix composite structures include joining at least two lamina together to form a flexible ceramic matrix composite structure. Ceramic matrix composite structures include at least one region of reduced inter-laminar bonding at a selected location between lamina thereof. Thermal protection systems include at least one seal comprising a ceramic matrix composite material and have at least one region of reduced inter-laminar bonding at a selected location between lamina used to form the seal. Methods of forming thermal protection systems include providing one or more such seals between adjacent panels of a thermal protection system.

The present invention relates to a sealing lid for a package containing an optical element. For the sealing lid, a translucent material such as glass that can transmit light such as visible light is used. The present invention includes a lid main body made of the translucent material. The lid main body includes a joining region having a frame shape corresponding to an outer circumferential shape of the lid main body. A plurality of pieces of brazing material made of a eutectic alloy are fused on the joining region of the lid main body. An arrangement state of the brazing material includes aligning spherical pieces of brazing material continuously to form a frame shape along the joining region.

The invention relates to a method of making a sink comprising: cutting out material that will constitute a bottom of the sink; making a hole for a drain in the bottom of the sink; supporting the edges of the bottom of the sink on a flat support and applying a mechanical force on the rim of the hole for the drain in the bottom of the sink; subjecting the bottom of the sink to a gradual and stepwise heating such that the mechanical force applied deforms said surface; cooling a flat slab; placing additional flat slabs around the first slab, on the sides thereof, to constitute the sides of the sink; externally coating the assembly made with a reinforcement comprising resins, glass fiber, mineral fillers, etc.; and bonding the upper part of the assembly made with the countertop where the sink is located.

Provided is at least any of a layered body, which has a change in texture derived from zirconia, particularly a change in translucency and is suitable as a dental prosthetic member, a precursor thereof, or a method for producing these. There is provided a layered body having a structure in which two or more layers containing zirconia containing a stabilizer are layered, the layered body including at least: a first layer containing zirconia having a stabilizer content of higher than or equal to 4 mol %; and a second layer containing zirconia having a stabilizer content different from that of the zirconia contained in the first layer.

There is provided at least any of a layered body which has a change in color tone and in which it is unnecessary to select a colorant and the content of the colorant in consideration of a difference in the sintering behavior between layers, a precursor thereof, or a method for producing these. Provided is a layered body which has a structure, in which two or more layers containing stabilizer-containing zirconia and a colorant are layered, and in which types and contents of the colorants contained in the layers are equal to each other, the layered body including at least: a first layer containing a colorant and zirconia which has a stabilizer content of higher than or equal to 3.3 mol %; and a second layer containing a colorant and zirconia which has a stabilizer content different from that of the zirconia contained in the first layer.

A method of processing a ceramic matrix composite (CMC) component includes extracting silicon from a surface region of the CMC component such that free silicon is present in the surface region at a reduced amount of about 5 vol. % or less. The extraction comprises contacting the surface region with a wicking medium comprising an element reactive with silicon. The extraction is carried out at an elevated temperature prior to assembling the CMC component with a metal component.

A method of processing a ceramic matrix composite (CMC) component includes extracting silicon from a surface region of the CMC component such that free silicon is present in the surface region at a reduced amount of about 5 vol. % or less. The extraction comprises contacting the surface region with a wicking medium comprising an element reactive with silicon. The extraction is carried out at an elevated temperature prior to assembling the CMC component with a metal component.

A method for producing a ceramic-aluminum bonded body obtained by bonding a ceramic member and an aluminum member, the aluminum member before bonding being composed of aluminum having a purity of 99.0 mass % or higher and 99.9 mass % or lower, includes a heat treatment step of subjecting the aluminum member to a heat treatment in a range of 400 C. or higher and lower than a solidus temperature, and a bonding step of bonding the aluminum member after the heat treatment step and the ceramic member via a brazing filler material including Si.