A ceramic bonded body may include a first member, a second member, a joining layer between the first member and the second member, and a covering layer which covers the joining layer and is located over the first member and the second member. The first member and the second member may include aluminum nitride-based ceramic. The joining layer and the covering layer may include at least aluminum, calcium, yttrium, and oxygen where, in 100 mass % of all of the constituents configuring the joining layer and the covering layer, the aluminum is 21 mass % or more converted to oxides, the calcium is 21 mass % or more converted to oxides, and the sum of the aluminum and the calcium converted to oxides is 86 mass % or more. The covering layer has a content of yttrium converted to oxides greater than that of the joining layer.

A ceramic joined body includes a first aluminum oxide-based sintered body, a second aluminum oxide-based sintered body, an aluminum oxide-based joint layer located between the first aluminum oxide-based sintered body and the second aluminum oxide-based sintered body, and an aluminum oxide-based protrusion connected to the aluminum oxide-based joint layer, where the average diameter for closed pores of the aluminum oxide-based projection is 0.8 times or more and 1.5 times or less as large as the average diameter for closed pores for each of the first aluminum oxide-based sintered body and the second aluminum oxide-based sintered body.

A power module substrate 10 is provided with: an insulating substrate 1; and a metal sheet 2 that is joined to the insulating substrate 1 via a brazing material 3, wherein regarding the surface roughness, in the thickness direction, of the lateral surface of the metal sheet 2, the surface roughness of a corner 2a farthest from the center of the metal sheet 2 is larger than the surface roughness of plane parts 2b, which bound the corner, in at least a plan view. Also provided is a power module 100 which is formed by mounting an electronic component 40 on this power module substrate 10.

The present invention provides a silicon nitride circuit board in which metal plates are attached on front and rear sides of a silicon nitride substrate having a three-point bending strength of 500 MPa or higher, with attachment layers interposed therebetween, wherein assuming that a thickness of the metal plate on the front side is denoted by t1, and a thickness of the metal plate on the rear side is denoted by t2, at least one of the thicknesses t1 and t2 is 0.6 mm or larger, a numerical relation: 0.10|t1t2|0.30 mm is satisfied, and warp amounts of the silicon nitride substrate in a long-side direction and a short-side direction both fall within a range from 0.01 to 1.0 mm. Due to above configuration, TCT properties of the silicon nitride circuit board can be improved even if the thicknesses of the front and rear metal plates are large.

A method includes providing a ceramic insert on a mandrel, the mandrel and the ceramic insert together define a peripheral working surface, forming a fiber preform by wrapping a fiber layer around the mandrel and the ceramic insert so as to conform to the peripheral working surface, removing the mandrel from the fiber preform to leave a cavity in the fiber preform, the ceramic insert remaining in the fiber preform and bordering the cavity, and densifying the fiber preform with a ceramic matrix to form a gas turbine engine component.

Provided is a gas sensor free from an unbonded space being in communication with an internal space. A gas sensor, which includes a sensor element including a plurality of layers that are bonded and formed of an oxygen-ion conductive solid electrolyte and which reduces a predetermined gas component of a measurement gas to identify a concentration of the gas component on the basis of a current flowing through the solid electrolyte, includes an internal space in which a measurement gas having the ability to reduce the gas component is provided. Of the plurality of layers, an interlaminar bonding layer, which bonds a layer forming a bottom surface of the internal space and a layer forming a side surface of the internal space, projects into the internal space.

A composite body including a substrate and a forming portion which is composed of a composite phase containing a perovskite oxide and a metal oxide different from the perovskite oxide and which is formed on the substrate. The composite body may be a composite body manufactured by a manufacturing method including a forming step of firing in an oxidizing atmosphere, a laminated body in which an inorganic raw material powder containing a compound powder and a metal powder is disposed on a substrate so as to form a forming portion composed of a composite phase containing a perovskite oxide and a metal oxide different from the perovskite oxide on the substrate.

A method of forming a ceramic matrix composite component is provided. The method includes applying a first amount of adhesive across a surface of a release film, providing a first ceramic foam panel including a plurality of channels formed on a first side of the first ceramic foam panel, contacting the first ceramic foam panel and the release film such that adhesive transfers to the first side of the first ceramic foam panel, and coupling the first ceramic foam panel to a second ceramic foam panel.

A circuit board includes a metal circuit plate, a metallic heat diffusing plate disposed below the metal circuit plate and having an upper surface and a lower surface, a metallic heat dissipating plate below the heat diffusing plate, an insulating substrate disposed between the metal circuit plate and the heat diffusing plate, and an insulating substrate disposed between the heat diffusing plate and the heat dissipating plate. A grain diameter of metal grains contained in the heat diffusing plate decreases from each of the upper surface and the lower surface of the heat diffusing plate toward a center portion of the heat diffusing plate in a thickness direction.

The present invention provides a ceramic metal circuit board including a ceramic substrate and metal plates bonded to both surfaces of the ceramic substrate through respective bonding layers, wherein a metal film is provided on a surface of one metal plate bonded to one surface of the ceramic substrate; and at least a part of another metal plate bonded to another surface of the ceramic substrate is not provided with the metal film. Preferably, a protruding portion is formed as a portion of the bonding layer so as to protrude from a side surface of each of the metal plates. According to the above-described configuration, it is possible to provide a ceramic circuit board which is easy to use according to the parts to be bonded and is excellent in heat-cycle resistance characteristics.