Provided is a boron nitride sintered body including boron nitride particles and pores, the boron nitride sintered body having a sheet shape and a thickness of less than 2 mm. Provided is a method for manufacturing a boron nitride sintered body, the method including a sintering step of molding and heating a blend containing a boron carbonitride powder and a sintering aid to obtain a sheet-shaped boron nitride sintered body including boron nitride particles and pores, in which a thickness of the boron nitride sintered body obtained in the sintering step is less than 2 mm.

Ultra-lightweight aerogels and methods for fabricating such aerogels from ammonia borane and a support structure, where the support structure is either two-dimensional nanostructures, or hydrocarbon polymer colloids. The components are mixed, then annealed. The properties of the disclosed aerogels can be tuned by controlling the ratio between the support structure and the ammonia borane, or by infiltrating the aerogels with additives.

This disclosure relates to a polycrystalline cubic boron nitride, PCBN, composite material comprising cubic boron nitride, cBN, particles and a binder matrix material in which the cBN particles are dispersed. The binder matrix material comprises one or more superalloys.

A method for producing a hollow part made of a ceramic matrix composite material. The method includes shaping a hollow fibrous preform. A core of oxidizable material is housed or inserted into the preform. The method also includes consolidating the preform and extracting the core by oxidising the core.

Polycrystalline cubic boron nitride, PCBN, material and methods of making PCBN. A method includes providing a matrix precursor powder comprising particles having an average particle size no greater than 250 nm, providing a cubic boron nitride, cBN, powder comprising particles of cBN having an average particle size of at least 0.2 μm, intimately mixing the matrix precursor powder and the cBN powder, and sintering the intimately mixed powders at a temperature of at least 1100° C. and a pressure of at least 3.5 GPa to form the PCBN material comprising particles of cubic boron nitride, cBN dispersed in a matrix material.

A cubic boron nitride sintered body including cubic boron nitride and a binder phase, wherein a content of the cubic boron nitride is 40 volume % or more and 70 volume % or less; a content of the binder phase is 30 volume % or more and 60 volume % or less; an average particle size of the cubic boron nitride is 0.1 μm or more and 3.0 μm or less; the binder phase contains TiN and/or TiCN, and TiB.sub.2 and contains substantially no AIN and/or Al.sub.2O.sub.3, the binder phase has a TiB.sub.2 (101) plane that shows a maximum peak position (2θ) in X-ray diffraction of 44.2° or more; and I.sub.2/I.sub.1 is 0.10 or more and 0.55 or less, where denotes an X-ray diffraction intensity of a (111) plane of the cubic boron nitride and I.sub.2 denotes an X-ray diffraction intensity of a (101) plane of TiB.sub.2 of the binder phase.

A cubic boron nitride sintered body including cubic boron nitride and a binder phase, wherein a content of the cubic boron nitride is 40 volume % or more and 80 volume % or less; a content of the binder phase is 20 volume % or more and 60 volume % or less; an average particle size of the cubic boron nitride is 0.5 μm or more and 4.0 μm or less; the binder phase contains TiC and TiB.sub.2 and contains substantially no AlN and/or Al.sub.2O.sub.3; a (101) plane of TiB.sub.2 in the binder phase shows a maximum peak position (2θ) in X-ray diffraction of 44.2° or more; and a (200) plane of TiC in the binder phase shows a maximum peak position (2θ) in X-ray diffraction of less than 42.1°.

A preform for making a component of a braking system having a fibre-reinforced ceramic composite material, obtained by forming and subsequent pyrolysis of a pre-preg is described. Also described is a component of a braking system made wholly or in part from the preform, and a method for making a preform in a fibre-reinforced ceramic composite material.

A fiber comprises a bulk material comprising: one or more of carbon, silicon, boron, silicon carbide, and boron nitride; and a metal or metal alloy whose affinity for oxygen is greater than that of the bulk material. At least a first portion of the metal or metal alloy is present at the entrance to grain boundaries at the surface of the fiber and within the fiber to a depth of at least 1 micron from the fiber surface. A method of improving a fiber comprises heating a fiber in an inert atmosphere to 900-1300 C for sufficient time to allow at least some of a metal or metal alloy, placed on the fiber, to diffuse and/or flow into and along grain boundaries to a depth of at least 1 micron. The metal or metal alloy has a greater affinity for oxygen than that of the fiber bulk material.

A method of forming an activated coating composition is disclosed. The method includes providing (a) boron nitride, (b) carbon, (c) aluminum oxide and (d) a liquid carrier. Each of the boron nitride, carbon and aluminum oxide are in particulate form. The coating composition is activated to form an activated coating composition. The activated coating composition includes active components having from about 60.0 wt% to about 90.0 wt% boron nitride, from about 16 wt% to about 24 wt% carbon and from about 4 wt% to about 6 wt% aluminum oxide. A coating method, coated substrate and activated coating composition are also disclosed.