The invention relates to hydrocarbon conversion, to equipment and materials useful for hydrocarbon conversion, and to processes for carrying out hydrocarbon conversion, e.g., hydrocarbon pyrolysis processes. The hydrocarbon conversion is carried out in a reactor which includes at least one channeled member that comprises refractory and has an open frontal area≤55%. The refractory can include non-oxide ceramic.

Systems and methods for making ceramic powders configured with consistent, tailored characteristics and/or properties are provided herein. In some embodiments a system for making ceramic powders, includes: a reactor body having a reaction chamber and configured with a heat source to provide a hot zone along the reaction chamber; a sweep gas inlet configured to direct a sweep gas into the reaction chamber and a sweep gas outlet configured to direct an exhaust gas from the reaction chamber; a plurality of containers, within the reactor body, configured to retain at least one preform, wherein each container is configured to permit the sweep gas to flow therethrough, wherein the preform is configured to permit the sweep gas to flow there through, such that the precursor mixture is reacted in the hot zone to form a ceramic powder product having uniform properties.

Systems and methods for making ceramic powders configured with consistent, tailored characteristics and/or properties are provided herein. In some embodiments a system for making ceramic powders, includes: a reactor body having a reaction chamber and configured with a heat source to provide a hot zone along the reaction chamber; a sweep gas inlet configured to direct a sweep gas into the reaction chamber and a sweep gas outlet configured to direct an exhaust gas from the reaction chamber; a plurality of containers, within the reactor body, configured to retain at least one preform, wherein each container is configured to permit the sweep gas to flow therethrough, wherein the preform is configured to permit the sweep gas to flow there through, such that the precursor mixture is reacted in the hot zone to form a ceramic powder product having uniform properties.

A method for sintering metallic and/or non-oxide components includes completely encapsulating, in a metal halide salt, a green body comprising at least one metallic and/or non-oxide powder, and compressing the encapsulated green body so as to be gastight. The method further includes heating, together with a metal halide salt in the presence of oxygen up to sintering temperatures, the compressed, encapsulated green body. The method additionally includes at least partially dissolving, after cooling, the metal halide salt in a liquid so that the sintered component can be removed.

In one aspect, particle powder compositions are provided for article manufacture by various additive manufacturing techniques. A powder composition comprises a particle component comprising sintered cemented carbide particles having apparent density of at least 6 g/cm.sup.3.

Methods for preparing ceramic matrix composites using melt infiltration and chemical vapor infiltration are provided as well as the resulting ceramic matrix composites. The methods and products include the incorporation of sacrificial fibers to provide improved infiltration of the fluid infiltrant. The sacrificial fibers are removed, such as decomposed during pyrolysis, resulting in the formation of regular and elongate channels throughout the ceramic matrix composite. Infiltration of the fluid infiltrant can then take place using the elongate channels resulting in improved density and an improved ceramic matrix composite product.

The sintered material includes a powder-derived material containing one or both of a nitride and an oxynitride, each of which contains at least one first metal element selected from the group consisting of group 4 elements, group 5 elements and group 6 elements in the periodic table, the rate y1/x1 of the atomic ratio y1 of non-metal element atoms in the powder-derived material to the atomic ratio x1 of metal element atoms therein is greater than 1, and the powder-derived material has a cubic structure.

A method for controlling grain growth in articles of manufacture produced using nano-particle jetting additive manufacturing processes includes the steps of; providing or obtaining nanoparticles of a bulk material, providing or obtaining nanoparticles of a dopant material different from the bulk material, supplying the bulk material and the dopant material to a nano-particle jetting apparatus, and using the nano-particle jetting apparatus, building-up the article of manufacture in a layer-by-layer manner. Each layer includes a mixture of the bulk material particles and the dopant material particles. Furthermore, the method includes sintering the article of manufacture. During sintering, the presence of the dopant material mixed with the bulk material moderates the grain growth of the bulk material.

Optical additive manufacturing, including laser additive manufacturing systems, apparatus and methods using polymer derived ceramic build materials. Additive manufacturing build materials are made of polymer derived ceramic including SiOC, precures, cured materials, hard cured materials, and pyrolized materials. Polymer derived ceramic build materials are mixed with and used in conjunction with other build materials.

High-entropy ultra-high temperature ceramics (HE-UHTC) coatings deposited on substrates, as well methods for depositing the HE-UHTC coatings on the substrates, are provided. An HE-UHTC electrode can be fabricated via spark plasma sintering (SPS) and then a thin coating of the HE-UHTC can be deposited in a precision-controlled manner on a substrate via an electro-spark deposition process.