A method of forming a water resistant boundary on a fissile material for use in a water cooled nuclear reactor is described. The method comprises mixing a powdered fissile material selected from the group consisting of UN and U.sub.3Si.sub.2 with an additive selected from oxidation resistant materials having a melting or softening point lower than the sintering temperature of the fissile material, pressing the mixed fissile and additive materials into a pellet, sintering the pellet to a temperature greater than the melting point of the additive. Alternatively, if the melting point of the oxidation resistant particles is greater than the sintering temperature of UN or U.sub.3Si.sub.2, then the oxidation resistant particles can have a particle size distribution less than that of the UN or U.sub.3Si.sub.2

A method of forming a water resistant boundary on a fissile material for use in a water cooled nuclear reactor is described. The method comprises mixing a powdered fissile material selected from the group consisting of UN and U.sub.3Si.sub.2 with an additive selected from oxidation resistant materials having a melting or softening point lower than the sintering temperature of the fissile material, pressing the mixed fissile and additive materials into a pellet, sintering the pellet to a temperature greater than the melting point of the additive. Alternatively, if the melting point of the oxidation resistant particles is greater than the sintering temperature of UN or U.sub.3Si.sub.2, then the oxidation resistant particles can have a particle size distribution less than that of the UN or U.sub.3Si.sub.2.

Advanced environmental barrier coating bond coat systems with higher temperature capabilities and environmental resistance are disclosed. These bond coat systems can be applied to ceramic substrates such as SiC/SiC ceramic matrix composite substrates, and can provide protection from extreme temperature, mechanical loading and environmental conditions, such as in high temperature gas turbines. Example bond coat systems can include either an advanced silicon/silicide component, an oxide/silicate component, or a combination thereof.

A method of manufacturing a ceramic matrix composite component may include introducing a gaseous precursor into an inlet portion of a chamber that houses a porous preform and introducing a gaseous mitigation agent into an outlet portion of the chamber that is downstream of the inlet portion of the chamber. The gaseous precursor may include methyltrichlorosilane (MTS) and the gaseous mitigation agent may include hydrogen gas. The introduction of the gaseous precursor may result in densification of the porous preform(s) and the introduction of the gaseous mitigation agent may shift the reaction equilibrium to disfavor the formation of harmful and/or pyrophoric byproduct deposits, which can accumulate in an exhaust conduit 340 of the system.

A method of manufacturing a ceramic matrix composite component may include introducing a gaseous precursor into an inlet portion of a chamber that houses a porous preform and introducing a gaseous mitigation agent into an outlet portion of the chamber that is downstream of the inlet portion of the chamber. The gaseous precursor may include methyltrichlorosilane (MTS) and the gaseous mitigation agent may include hydrogen gas. The introduction of the gaseous precursor may result in densification of the porous preform(s) and the introduction of the gaseous mitigation agent may shift the reaction equilibrium to disfavor the formation of harmful and/or pyrophoric byproduct deposits, which can accumulate in an exhaust conduit 340 of the system.

A 3D printing method includes mixing a sintered component which is selected from the group comprising ceramic materials, ceramic material combinations, metal materials, metal material combinations and metal alloys, with at least one surface coating component which is selected from the group comprising boron nitride, graphene, carbon nanotubes, tungsten sulfide, tungsten carbide, molybdenum sulfide, molybdenum carbide, calcium fluoride, caesium molybdenum oxide sulfide, titanium silicon carbide and cerium fluoride, in a powder mixture; and laser sintering or laser melting the powder mixture in a selective laser sintering method or a selective laser melting method.

An article having a substrate that includes a ceramic or a ceramic matrix composite, a bond layer on the substrate that includes silicon metal and a boria stabilizing agent, and at least one additional layer on the bond layer.

Disclosed herein are a ceramic particle comprising a ceramic core substrate and a conformal coating of a sintering aid film on a surface of the core substrate, wherein the conformal coating includes a plurality of distributed islands of the sintering aid film across the surface of the core substrate; methods for producing the ceramic particle by ALD or MLD; and methods of using the coated ceramic particles in additive manufacturing or in solid oxide fuel cells. In one example, the film may have a thickness of less than three nanometers. The disclosed ceramic particle may be non-reactive with water.

A solid electrolyte includes a particle having a first portion that includes, as constituent elements, lanthanum (La), lithium, titanium and oxygen, and a second portion that covers a surface of the first portion and includes, as constituent elements, lanthanum, lithium, titanium and oxygen and in which sulfur is coupled to an oxygen deficient portion and at least a surface is oxidized.

The present invention relates to a method for preparing a phase-separated lead telluride-lead sulfide nanopowder using solution synthesis and a phase-separated lead telluride-lead sulfide nanopowder prepared by the method. The method includes: (a) mixing tellurium and a first solvent, followed by ultrasonic irradiation to prepare a tellurium precursor solution; (b) mixing an organosulfur compound and a second solvent, followed by ultrasonic irradiation to prepare a sulfur precursor solution; (c) mixing lead oxide, a third solvent, and a fourth solvent and heating the mixture to prepare a lead precursor solution; (d) adding the tellurium precursor solution to the lead precursor solution and allowing the mixture to react; (e) adding the sulfur precursor solution to the reaction mixture of step (d) and allowing the resulting mixture to react; and (f) cooling the reaction mixture of step (e) to room temperature to prepare a phase-separated lead telluride-lead sulfide nanopowder.