A complex composite particle is made of a coal dust and binder composite that is pyrolyzed. Constituent portions of the composite react together causing the particles to increase in density and reduce in size during pyrolyzation, yielding a particle suitable for use as a proppant or in a composite structure.

A method of fabricating a part out of composite material, includes forming a fiber texture from refractory fibers; impregnating the fiber texture for a first time with a first slip containing first refractory particles; eliminating the liquid phase from the first slip so as to leave within the texture only the first refractory particles; impregnating the fiber texture for a second time with a second slip containing second refractory particles; eliminating the liquid phase from the second slip so as to leave within the texture only the second refractory particles and obtain a fiber preform filled with the first and second refractory particles; and sintering the first and second refractory particles present in the fiber preform in order to form a refractory matrix in the preform.

diboride-silicon carbide (SiC) multiphase ceramic, including: (S1) mixing a transition metal oxide mixed powder, nano carbon black and a silicon hexaboride (SiB.sub.6) powder to obtain a precursor powder; and (S2) subjecting the precursor powder to pressureless sintering to obtain the high-entropy carbide-high-entropy diboride-SiC multiphase ceramic with a relative density of 96% or more.

A method for forming an ultra-high temperature (UHT) composite structure includes dispensing a polymeric precursor with a spinneret biased at a first DC voltage; forming a plurality of nanofibers from the polymeric precursor; receiving the plurality of nanofibers with a collector biased at a second DC voltage different than the first DC voltage; and changing a direction of movement of the plurality of nanofibers between the spinneret and the collector with a plurality of magnets having a magnetic field by adjusting the magnetic field.

A cubic boron nitride (cBN)-based composite including about 30-65 vol. % cBN, about 15-45 vol. % titanium (Ti)-containing binders, about 2-20 vol. % zirconium dioxide (ZrO.sub.2), about 3-15 vol. % cobalt-tungsten-borides (Co.sub.xW.sub.yB.sub.z), and about 2-15 vol. % aluminum oxide (Al.sub.2O.sub.3).

A cubic boron nitride sintered body has between 50% and 75% cubic boron nitride by volume and between 25% and 50% binder phase by volume, and inevitable impurities. The binder phase contains an Al compound and a Zr compound. The Al compound contains Al and one or more of N, O and B; and the Zr compound contains Zr and one or more of C, N, O and B. At a polished surface of the cubic boron nitride sintered body, 40% or more of the Zr compounds satisfy the ratio 0.25≦n/N≦0.8, where: N represents the number of line segments drawn radially at equal intervals from a center of gravity of a given Zr compound to a boundary with a non-Zr compound; and n represents the number among those N line segments which intersect a boundary between the given Zr compound and cubic boron nitride.

A layer by layer additive manufacturing system from liquid polymers for producing dense and defect free polymer-derived ceramic bodies of a three dimensional architecture.

Disclosed is a modified preceramic polymer having a polymer backbone consisting of silicon or a combination of silicon and carbon; and a pendant modifier bonded to the backbone wherein the modifier includes silicon, boron, aluminum, a transition metal, a refractory metal, or a combination thereof. The modified preceramic polymer can be used to form a ceramic matrix composite.

The present invention provides for materials and methods of making metal and ceramic matrix composites reinforced with boron nitride nanomaterials for improved physical properties such as hardness, fracture toughness, and bend strength.

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).