Inventive manufacture of CrB.sub.2—Al.sub.2O.sub.3 composites is based on pressureless sintering. According to typical inventive practice, CrB.sub.2 powder and Al.sub.2O.sub.3 powder are mixed together in selected volumetric proportions so that the volume of the CrB.sub.2 does not exceed 50% of the overall volume of the CrB.sub.2—Al.sub.2O.sub.3 mixture. The CrB.sub.2—Al.sub.2O.sub.3 mixture is shaped into a green body. The green body is pressureless sintered in a non-oxidizing atmosphere at a firing temperature in the approximate range between 1600° C. and 2050° C. The present invention succeeds in preparing, via pressureless sintering, a proportionality-associated range of compositions in the CrB.sub.2—Al.sub.2O.sub.3 system, which is a potentially “advanced” ceramic system. A typical inventively fabricated CrB.sub.2—Al.sub.2O.sub.3 composite is inventively configured in a complex shape, and has “advanced” material (e.g., mechanical) properties that are favorable for a contemplated application. Inventive manufacture of ceramic-ceramic composites is thus dually attributed, and uncommonly so, with complex shape-ability and advanced capability.

A method for manufacturing a part made of composite material includes injecting into a fibrous texture a slurry including at least one powder of refractory ceramic particles suspended in a liquid phase, filtering the liquid phase of the slurry and retaining the powder of refractory ceramic particles inside the texture so as to obtain a fibrous preform loaded with refractory ceramic particles, densifying the fibrous texture by treatment of the refractory ceramic particles present in the fibrous texture in order to form a refractory matrix in the texture. The method further includes, before injecting the slurry under pressure, pre-saturating the fibrous texture with a carrier fluid consisting in injecting into said texture a carrier fluid.

An armor component including a body having a first portion including calcium boride compounds include non-stoichiometric calcium boride (CaB.sub.x) and stoichiometric calcium boride (CaB.sub.6) and having a density of at least about 80% theoretical density. In one aspect, the first portion can include a first phase comprising silicon carbide (SiC) and a second phase comprising calcium boride (CaB.sub.6). In another aspect, the first portion can further include a third phase comprising boron carbide (B.sub.4C).

An object shaping method includes a step of forming a powder layer using first powder, a step of placing second powder having an average particle diameter smaller than an average particle diameter of the first powder at a part of a region of the powder layer, and a first heating step of heating the powder layer in which the second powder is placed. The average particle diameter is equal to or larger than 1 nm and equal to or smaller than 500 nm, and the first heating step performs heating the powder layer at a temperature at which particles contained in the second powder are sintered or melted.

An article includes a ceramic matrix composite wall that defines at least a side of a passage. The ceramic wall includes a ceramic matrix composite flow turbulator that projects into the passage. The flow turbulator is formed of ceramic matrix composite. The ceramic matric composite of the wall comprises woven fibers that are dispersed in a ceramic body matrix. An airfoil and a gas turbine engine are also disclosed.

Methods of making a ceramic of a Group 13-15 type or a Group 13-15-16 type by thermolyzing a discrete molecular precursor to the ceramic in an oxygen-containing atmosphere. In some embodiments, the discrete molecular precursor is bench-stable and comprises a Lewis acid-base pair or small cyclic compound containing at last one Group 13 element and at least one Group 15 element but does not include indium and phosphorus in combination with one another unless a Group 16 element is present. The thermolysis can be carried out in air, at atmospheric pressure, and at a temperature below about 400° C., if desired. In some embodiments, the discrete molecular precursor can be placed in a mold having a desired shape and the thermolysis performed while the discrete molecular precursor is in the mold so as to produce a ceramic product having the desired shape.

A fuel assembly for a nuclear reactor, a fuel rod of the fuel assembly, and a ceramic nuclear fuel pellet of the fuel rod are disclosed. The fuel pellet includes a first fissile material of UB.sub.2, The boron of the UB.sub.2 is enriched to have a concentration of the isotope .sup.11B that is higher than for natural B.

A method for injecting a loaded suspension into a fibrous texture having a three-dimensional or multilayer weaving includes the injection of a suspension containing a powder of solid particles into the volume of the fibrous texture. The injection of the loaded suspension is carried out by at least one hollow needle in communication with a loaded suspension supply device, each needle being movable in at least one direction extending between a first face and a second opposite face of the fibrous texture so as to inject the loaded suspension at one or more determined depths in the fibrous texture.

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 composition suitable for 3D printing in the form of a filament that includes 45 to 60% (v/v) of a metal and/or ceramic powder; 7% to 25% (v/v) of a binder; and at least 5% (v/v) of a mixture of medium and high vinyl acetate proportion poly (ethylene-vinyl acetate). Also, a filament coil, a 3D printing machine, a green shaped body and a shaped body having the composition. Lastly, a method for 3D printing by using the composition.