A process for depositing a coating on short fibres of carbon or silicon carbide from a coating precursor, the short fibres having a length of between 50 μm and 5 mm, the process including at least heating the short fibres by placing a mixture including the fibres and a liquid phase of the coating precursor in a microwave field so as to bring the surface of the fibres to a temperature allowing the coating on the fibres from the coating precursor to be formed by calefaction.

Multifunctional Boron Nitride nanotube-Boron Nitride (BN—BN) nanocomposites for energy transducers, thermal conductors, anti-penetrator/wear resistance coatings, and radiation hardened materials for harsh environments. An all boron-nitride structured BN—BN composite is synthesized. A boron nitride containing precursor is synthesized, then mixed with boron nitride nanotubes (BNNTs) to produce a composite solution which is used to make green bodies of different forms including, for example, fibers, mats, films, and plates. The green bodies are pyrolized to facilitate transformation into BN—BN composite ceramics. The pyrolysis temperature, pressure, atmosphere and time are controlled to produce a desired BN crystalline structure. The wholly BN structured materials exhibit excellent thermal stability, high thermal conductivity, piezoelectricity as well as enhanced toughness, hardness, and radiation shielding properties. By substituting with other elements into the original structure of the nanotubes and/or matrix, new nanocomposites (i.e., BCN, BCSiN ceramics) which possess excellent hardness, tailored photonic bandgap and photoluminescence, result.

A method for manufacturing a part made of composite material includes forming a ceramic matrix phase in pores of a fibrous preform by pyrolysis of a cross-linked copolymer ceramic precursor, the cross-linked copolymer including a first precursor macromolecular chain of a first ceramic having free carbon, and a second precursor macromolecular chain of a second ceramic having free silicon, the first macromolecular chain being bonded to the second macromolecular chain by cross-linking bridges including a bonding structure of formula *.sup.1—X—*.sup.2; in this formula, X designates boron or aluminium, -*.sup.1 designates the bond to the first macromolecular chain and -*.sup.2 the bond to the second macromolecular chain.

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.

A method may include depositing a sacrificial support material on or adjacent to a build surface. The sacrificial support material may be configured to support a continuous reinforcement material during an additive manufacturing technique. The method also may include extruding the continuous reinforcement material from an additive manufacturing device such that at least a portion of the continuous reinforcement material contacts and is supported by the sacrificial support material; and removing the sacrificial support material to result in a feature defined at least in part by the continuous reinforcement material at the absence of sacrificial support material.

A nano-inorganic composition according to an embodiment of the present disclosure includes and is not limited to excellent mechanical characteristics such as surface hardness and wear characteristics, chemical stability such as water resistance, acid resistance, and alkali resistance, and excellent thermal stability, as the composition is comprised of inorganic materials. In addition, the nano-inorganic composition may be controlled to have super-hydrophilic, hydrophilic, or hydrophobic properties, depending on coating methods. The nano-inorganic composition also has excellent surface contamination resistance and easy-clean properties depending on the characteristics of the thin film coating. Also, the nano-inorganic composition has excellent optical properties such as light transmittance and light reflectance.

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.

A ceramic aerogel includes a porous framework including interconnected double-paned wall structures of a ceramic material, wherein each double-paned wall structure includes a pair of walls spaced apart by a gap.

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 method for manufacturing a part made of composite material includes forming a ceramic matrix phase in pores of a fibrous preform by pyrolysis of a cross-linked copolymer ceramic precursor, the cross-linked copolymer including a first precursor macromolecular chain of a first ceramic having free carbon, and a second precursor macromolecular chain of a second ceramic having free silicon, the first macromolecular chain being bonded to the second macromolecular chain by cross-linking bridges including a bonding structure of formula *.sup.1—X—*.sup.2; in this formula, X designates boron or aluminium, -*.sup.1 designates the bond to the first macromolecular chain and -*.sup.2 the bond to the second macromolecular chain.