A ceramic matrix composite (CMC) is formed by infiltrating a metal or alloy into a fiber preform in a reactor or furnace that is separated into multiple discrete temperature zones. The gradual cooling of the CMC is controlled, such that upon solidification, a narrow, planar, solidification front is created which allows the expanding metal or alloy to move into a hotter section of the fiber preform, opposed to the surface of the CMC. A discrete solidification front is established that moves through the ceramic matrix composite (CMC) as the composite cools.

An article including carbon-carbon composite substrate may be treated with an antioxidant coating prior to use in an oxidizing environment. The antioxidant coating may be configured to reduce oxidation at an external surface of the C-C composition and reduce ingress of oxidants into pores or other open passages defined by the C-C composite substrate to avoid internal oxidation. An example article includes a C-C composite substrate, a bond coat, and an antioxidant coating. The C-C composite substrate defines a friction surface and a non-friction surface. The bond coat is disposed on the non-friction surface. The antioxidant coating may be disposed on at least a portion of the bond coat. The antioxidant coating may include ytterbium disilicate and a sintering aid.

The invention relates to a method for producing a non-oxide ceramic powder comprising a nitride, a carbide, a boride or at least one MAX phase with the general composition Mn+1AXn, where M=at least one element from the group of transition elements (Sc, Ti, V, Cr, Zr, Nb, Mo, Hf and Ta), A=at least one A group element from the group (Si, Al, Ga, Ge, As, Cd, In, Sn, Tl and Pb), X=carbon (C) and/or nitrogen (N) and/or boron (B), and n=1, 2 or 3. According to the invention, corresponding quantities of elementary starting materials or other precursors are mixed with at least one metal halide salt (NZ), compressed (pellet), and heated for synthesis with a metal halide salt (NZ). The compressed pellet is first enveloped with another metal halide salt, compressed again, arranged in a salt bath and heated therewith until the melting temperature of the salt is exceeded. Optionally, melted silicate can be added, which prevents the salt from evaporating at high temperatures. Advantageously, the method can be carried out in the presence of air.

A method includes forming a ceramic member that has a plurality of closed pores within a ceramic matrix. The forming includes compacting a ceramic powder to form intra-particle pores between particles of the ceramic powder, and sintering the compacted ceramic powder to cause diffusion of the ceramic powder and formation of the ceramic matrix. The diffusion does not fill the intra-particle pores and leaves the closed pores.

A ceramic electronic component includes a body including a dielectric layer and an internal electrode; and an external electrode disposed on the body and connected to the internal electrode. The dielectric layer includes a plurality of crystal grains and a grain boundary disposed between adjacent crystal grains. A ratio (C2/C1) of an Mg content (C2) of the grain boundary to an Mg content (C1) of at least one of the plurality of crystal grains is 3 or more.

A thermally conductive composite particle, including: a core portion including an inorganic particle; and a shell portion including a nitride particle and covering the core portion, is provided. The thermally conductive composite particle is a sintered body.

A composite ceramic with improved mechanical performance and a preparation method therefor. The composite ceramic comprises fluorescent powder, a ceramic matrix, and an optional sintering aid. The weight ratio of the fluorescent powder to the ceramic matrix is from 3:17 to 9:1, and the relative density of the composite ceramic is greater than 95%. The preparation method comprises using core shell-structured coated fluorescent powder as a raw material, and ball-milling and sintering the raw material to obtain the composite ceramic.

A process for producing a highly carbonaceous fibre or set of fibres including combining a structured precursor comprising a hydrocellulose fibre or a set of fibres, and an unstructured precursor, including lignin or a lignin derivative in the form of a solution having a viscosity less than 15,000 mPa.Math.s.sup.1 at the temperature at which the combination step takes place, in order to obtain a hydrocellulose fibre or set of fibres coated with the lignin or lignin derivative, wherein the process further includes a step of thermal and dimensional stabilization of the hydrocellulose fibre or set of fibres covered with the lignin in order to obtain a hydrocellulose fibre or set of fibres covered with a deposit of lignin or lignin derivative, and a carbonization step of the hydrocellulose fibre or set of fibres coated with a lignin deposit in order to obtain a highly carbonaceous fibre or set of fibres.

A method of melt infiltrating a green ceramic matrix composite (CMC) article, wherein the green CMC article includes a ceramic reinforcing structure. The method includes heating a localized region of the green CMC article; melting a metal alloy infiltrant to form a molten metal alloy; and introducing the molten metal alloy into the localized region to infiltrate the reinforcing structure of the green CMC article with the metal alloy infiltrant and form the CMC article.

Cemented carbide powder compositions are provided for use in the production of various articles by one or more additive manufacturing techniques. In one aspect, a powder composition comprises sintered cemented carbide particles having at least a bimodal particle size distribution, wherein sintered cemented carbide particles of a first mode exhibit a D50 particle size of 25 m to 50 m, and sintered cemented carbide particles of a second mode exhibit a D50 of less than 10 m, and the powder composition has an apparent density of 3.5 g/cm.sup.3 to 8 g/cm.sup.3.