C04B41/5392

METHOD FOR PRODUCING CERAMIC MULTILAYERED TUBE USED AS CLADDING FOR FUEL ELEMENT IN NUCLEAR POWER PLANT

The method includes forming an inner monolithic layer from crystals of beta phase stoichiometric silicon carbide on a carbon substrate in the form of a rod by chemical methylsilane vapor deposition in a sealed tubular hot-wall CVD reactor. The method further includes forming a central composite layer over the inner monolithic layer by twisting continuous beta phase stoichiometric silicon carbide fibers into tows, transporting the tows to a braiding machine, and forming a reinforcing thread framework. A pyrocarbon interface coating is built up by chemical methane vapor deposition in a sealed tubular hot-wall CVD reactor. Then, a matrix is formed by chemical methylsilane vapor deposition in the reactor. A protective outer monolithic layer is formed from crystals of beta phase stoichiometric silicon carbide over the central composite layer by chemical methylsilane vapor deposition in a CVD reactor. And then the carbon substrate is removed from the fabricated semi-finished product.

Method for producing ceramic multilayered tube used as cladding for fuel element in nuclear power plant

The method includes forming an inner monolithic layer from crystals of beta phase stoichiometric silicon carbide on a carbon substrate in the form of a rod by chemical methylsilane vapor deposition in a sealed tubular hot-wall CVD reactor. The method further includes forming a central composite layer over the inner monolithic layer by twisting continuous beta phase stoichiometric silicon carbide fibers into tows, transporting the tows to a braiding machine, and forming a reinforcing thread framework. A pyrocarbon interface coating is built up by chemical methane vapor deposition in a sealed tubular hot-wall CVD reactor. Then, a matrix is formed by chemical methylsilane vapor deposition in the reactor. A protective outer monolithic layer is formed from crystals of beta phase stoichiometric silicon carbide over the central composite layer by chemical methylsilane vapor deposition in a CVD reactor. And then the carbon substrate is removed from the fabricated semi-finished product.

THREE-DIMENSIONAL WEAVE WITH SACRIFICIAL Z-FIBERS FOR IMPROVED CERAMIC MATRIX COMPOSITE MICROSTRUCTURE
20240308927 · 2024-09-19 ·

A method of forming a ceramic matrix composite includes three-dimensionally weaving a fibrous preform, the preform including a plurality of warp tows, a plurality of weft tows, and a plurality of z-fibers passing orthogonally between the plurality of warp and the plurality of weft tows. The method further includes debulking the preform, decomposing the plurality of z-fibers to form a respective plurality of z-channels in the preform, and densifying the preform with a ceramic matrix.

SELECTIVE ETCH OF TITANIUM CARBIDE MATERIALS USING OXIDATION

A method of dry etching a titanium carbide material of a substrate includes performing an oxidation step and a fluorination step. The oxidation step includes exposing the titanium carbide material to an oxidizing agent to form an oxidized layer including titanium oxide species and remove carbon from the titanium carbide material by forming volatilized carbon oxide species. The fluorination step includes exposing the titanium oxide species of the oxidized layer to a fluorinating agent to remove titanium from the titanium carbide material by forming volatilized fluorinated titanium oxide species. The method may be repeated as a cycle in situ within a processing chamber. The method may further include a substitution step that includes exposing a metallic fluoride species formed during the fluorination step to a substitution agent to remove metallic species from the titanium carbide material by forming volatilized metallic fluoride species.