Methods for forming a ceramic matrix composite from a melt infiltrated and melt extracted preform that has residual silicon within open pore channels therein are provided. The method may include: introducing a carbon yielding resin into the open pore channels; heating the preform to produce elemental carbon from the carbon yielding resin within the open pore channels; and further heating the elemental carbon to react with the residual silicon to form SiC within the open pore channels to form the ceramic matrix composite.

An article includes a substrate and a coating on the substrate. The coating includes a compound of aluminum, boron and nitrogen in a continuous chemically bonded network having AlN bonds and BN bonds. Also disclosed is an article wherein the substrate is a plurality of fibers and the coating is a conformed coating of a compound of aluminum, boron and nitrogen having AlN bonds and BN bonds. The fibers are disposed in a matrix. Also disclosed is a method of protecting an article from environmental conditions. The method includes protecting a substrate that is susceptible to environmental chemical degradation using a coating that includes a compound of aluminum, boron and nitrogen having AlN bonds and BN bonds.

This invention provides resin formulations which may be used for 3D printing and pyrolyzing to produce a ceramic matrix composite. The resin formulations contain a solid-phase filler, to provide high thermal stability and mechanical strength (e.g., fracture toughness) in the final ceramic material. The invention provides direct, free-form 3D printing of a preceramic polymer loaded with a solid-phase filler, followed by converting the preceramic polymer to a 3D-printed ceramic matrix composite with potentially complex 3D shapes or in the form of large parts. Other variations provide active solid-phase functional additives as solid-phase fillers, to perform or enhance at least one chemical, physical, mechanical, or electrical function within the ceramic structure as it is being formed as well as in the final structure. Solid-phase functional additives actively improve the final ceramic structure through one or more changes actively induced by the additives during pyrolysis or other thermal treatment.

This invention provides resin formulations which may be used for 3D printing and pyrolyzing to produce a ceramic matrix composite. The resin formulations contain a solid-phase filler, to provide high thermal stability and mechanical strength (e.g., fracture toughness) in the final ceramic material. The invention provides direct, free-form 3D printing of a preceramic polymer loaded with a solid-phase filler, followed by converting the preceramic polymer to a 3D-printed ceramic matrix composite with potentially complex 3D shapes or in the form of large parts. Other variations provide active solid-phase functional additives as solid-phase fillers, to perform or enhance at least one chemical, physical, mechanical, or electrical function within the ceramic structure as it is being formed as well as in the final structure. Solid-phase functional additives actively improve the final ceramic structure through one or more changes actively induced by the additives during pyrolysis or other thermal treatment.

This invention provides resin formulations which may be used for 3D printing and pyrolyzing to produce a ceramic matrix composite. The resin formulations contain a solid-phase filler, to provide high thermal stability and mechanical strength (e.g., fracture toughness) in the final ceramic material. The invention provides direct, free-form 3D printing of a preceramic polymer loaded with a solid-phase filler, followed by converting the preceramic polymer to a 3D-printed ceramic matrix composite with potentially complex 3D shapes or in the form of large parts. Other variations provide active solid-phase functional additives as solid-phase fillers, to perform or enhance at least one chemical, physical, mechanical, or electrical function within the ceramic structure as it is being formed as well as in the final structure. Solid-phase functional additives actively improve the final ceramic structure through one or more changes actively induced by the additives during pyrolysis or other thermal treatment.

Disclosed is a method of making a high temperature fiber including incorporating an inorganic atom into a polymer precursor fiber to form a modified polymer precursor fiber and converting the modified polymer precursor fiber to a high temperature fiber having a bonded inorganic atom.

Methods for coating a fiber are provided. The method can include unwinding a silicon carbide-containing fibrous material from a bobbin rotatably mounted around an axle and forming a boron nitride coating onto the silicon carbide-containing fibrous material. The bobbin is moved along the axial direction such that the silicon carbide-containing fibrous material defines an unwind angle with the axial direction, with the unwind angle being maintained between about 80 to about 100.

A method for manufacturing a resonator in a substrate, including: a) modifying a structure of at least one region of the substrate to make the at least one region more selective; b) etching the at least one region to selectively manufacture the resonator.

Nuclear fuel structures and methods for fabricating are disclosed herein. The nuclear fuel structure includes a plurality of fibers arranged in the structure and a multilayer fuel region within at least one fiber of the plurality of fibers. The multilayer fuel region includes an inner layer region made of a nuclear fuel material, and an outer layer region encasing the nuclear fuel material. A plurality of discrete multilayer fuel regions may be formed over a core region along the at least one fiber, the plurality of discrete multilayer fuel regions having a respective inner layer region of nuclear fuel material and a respective outer layer region encasing the nuclear fuel material. The plurality of fibers may be wrapped around an inner rod or tube structure or inside an outer tube structure of the nuclear fuel structure, providing both structural support and the nuclear fuel material of the nuclear fuel structure.

A method of forming a composite article includes impregnating an inorganic fiber preform with a slurry composition. The slurry composition includes a particulate, a solvent, and a pre-gellant material. Gelling of the pre-gellant material in the slurry composition is initiated to immobilize the particulate and yield a gelled article, and substantially all solvent is removed from the gelled article to form a green composite article. The green composite article is then infiltrated with a molten infiltrant to form the composite article.