A seal assembly for a gas turbine engine according to an example of the present disclosure includes a seal that has a main body extending circumferentially between opposed mate faces. The main body has a sealing portion and an engagement portion extending outwardly from sealing portion along at least one of the mate faces. The main body has a core that has one or more core plies having a first fiber construction and arranged to establish an internal cavity. An overwrap has one or more overwrap plies having a second fiber construction and arranged to follow a perimeter of the one or more core plies to establish the engagement portion and the sealing portion, and the second fiber construction differs from the first fiber construction. The first fiber construction establishes a first target fiber volume fraction, the second fiber construction establishes a second target fiber volume fraction. A method of fabricating a seal for a gas turbine engine is also disclosed.

A method to form a machinable ceramic matrix composite comprises forming a porous ceramic multilayer on a surface of a fiber preform. In one example, the porous ceramic multilayer comprises a gradient in porosity in a direction normal to the surface. In another example, the porous ceramic multilayer includes low-wettability particles having a high contact angle with molten silicon, where an amount of the low-wettability particles in the porous ceramic multilayer varies in a direction normal to the surface. After forming the porous ceramic multilayer, the fiber preform is infiltrated with a melt, and the melt is cooled to form a ceramic matrix composite with a surface coating thereon. An outer portion of the surface coating is more readily machinable than an inner portion of the surface coating. The outer portion of the surface coating is machined to form a ceramic matrix composite having a machined surface with a predetermined surface finish and/or dimensional tolerance.

A knife includes a blade having a first side face and a second side face. The blade includes zirconia as a main component, and includes a cutting region including at least a ridge portion between the first side face and the second side face. When a portion including the cutting region in the first side face is referred to as a first cutting face, and a portion including the cutting region in the second side face is referred to as a second cutting face, the proportion of cubic crystals of zirconia in the first cutting face is larger than the proportion of cubic crystals of zirconia in the second cutting face.

The present invention relates to a composite material comprising wollastonite fibres embedded within a ceramic matrix. The wollastonite fibres are bonded to the ceramic matrix by a glassy bonding phase comprising a glass component comprising at least 80 wt % of oxides of calcium, silicon and aluminium. The material is used in the processing of molten metal, e.g. as a pump, degasser, flux injector or scrap submergence device.

A dielectric material includes a main component including barium titanate, a first additive containing zirconium in an amount of 2 at % or more and 10 at % or less with respect to titanium of the barium titanate, a second additive containing 0.2 at % or more and 3.5 at % or less of europium with respect to titanium of the barium titanate, rare earth elements other than europium being less than europium, a third additive containing 0.5 at % or more and 4.5 at % or less of manganese with respect to titanium of the barium titanate, and a fourth additive containing at least one of strontium and calcium in an amount of 0.1 at % or more and 3 at % or less with respect to titanium in the barium titanate.

A dielectric ceramic that includes multiple crystal grains, each of the multiple crystal grains having an interface, a barium titanate (BaTiO.sub.3)-based compound as a main component thereof, and a rare earth element. The dielectric ceramic has a cross-section in which the multiple crystal grains has a concentration varying region, a high concentration region, and a low concentration region. The concentration varying region has an RE/Ti ratio differing by 3% or more. The high concentration region has an RE/Ti ratio of 5% to 20%. The low concentration region has an RE/Ti ratio of 0% to 2%.

A method for manufacturing a multilayer varistor includes: a first step including providing a multilayer stack in which a plurality of green sheet layers, each containing a Zn oxide powder as a main component and a Pr oxide powder as a sub-component, and a plurality of internal electrode paste layers, each containing a Pd powder, are alternately stacked; and a second step including forming a sintered compact, including an internal electrode inside, by baking the multilayer stack. The second step includes: a first sub-step including baking the multilayer stack by setting an oxygen concentration in an atmosphere at 1000 ppm by volume or less while increasing a temperature from 500° C. to 800° C.; and a second sub-step including baking, after the first sub-step, the multilayer stack by setting the oxygen concentration in the atmosphere at 1000 ppm by volume or more while increasing the temperature to a maximum allowable temperature.

A silicon carbide-graphite composite is described, including (i) interior bulk graphite material and (ii) exterior silicon carbide matrix material, wherein the interior bulk graphite material and exterior silicon carbide matrix material inter-penetrate one another at an interfacial region therebetween, and wherein graphite is present in inclusions in the exterior silicon carbide matrix material. Such material may be formed by contacting a precursor graphite article with silicon monoxide (SiO) gas under chemical reaction conditions that are effective to convert an exterior portion of the precursor graphite article to a silicon carbide matrix material in which graphite is present in inclusions therein, and wherein the silicon carbide matrix material and interior bulk graphite material interpenetrate one another at an interfacial region therebetween. Such silicon carbide-graphite composite is usefully employed in applications such as implant hard masks in manufacturing solar cells or other optical, optoelectronic, photonic, semiconductor and microelectronic products, as well as in ion implantation system materials, components, and assemblies, such as beam line assemblies, beam steering lenses, ionization chamber liners, beam stops, and ion source chambers.

A crack self-healing functionally gradient material for ceramic cutting tools and a preparation method thereof. The material for ceramic cutting tools has a symmetrical gradient structure, and based on the percentage by mass, components of each layer include 50%-80% of Ti(C.sub.7,N.sub.3), 25%-5% of (W.sub.7,Ti.sub.3)C and 20%-0% of TiSi.sub.2; contents of components of layers that are symmetrical relative to a central layer are the same and a thickness is symmetrically distributed; a content of Ti(C.sub.7,N.sub.3) gradually increases from the surface layer to the central layer, contents of (W.sub.7,Ti.sub.3)C and Ti Si.sub.2 gradually decrease by 5% from the surface layer to the central layer, and the contents of Ni and Mo gradually increase from the surface layer to the central layer.

A silicon carbide-graphite composite is described, including (i) interior bulk graphite material and (ii) exterior silicon carbide matrix material, wherein the interior bulk graphite material and exterior silicon carbide matrix material inter-penetrate one another at an interfacial region therebetween, and wherein graphite is present in inclusions in the exterior silicon carbide matrix material. Such material may be formed by contacting a precursor graphite article with silicon monoxide (SiO) gas under chemical reaction conditions that are effective to convert an exterior portion of the precursor graphite article to a silicon carbide matrix material in which graphite is present in inclusions therein, and wherein the silicon carbide matrix material and interior bulk graphite material interpenetrate one another at an interfacial region therebetween. Such silicon carbide-graphite composite is usefully employed in applications such as implant hard masks in manufacturing solar cells or other optical, optoelectronic, photonic, semiconductor and microelectronic products, as well as in ion implantation system materials, components, and assemblies, such as beam line assemblies, beam steering lenses, ionization chamber liners, beam stops, and ion source chambers.