Provided is a boron nitride sintered body having a porous structure, the boron nitride sintered body including a lump particle formed by aggregation of primary particles of boron nitride and having a particle diameter of 15 μm or more. Provided is a method for manufacturing a boron nitride sintered body, the method including: a nitriding step of firing a raw material powder containing boron carbide in an atmosphere containing nitrogen to obtain a fired product including lump particles each having a core part with primary particles of boron carbonitride aggregated and a shell part surrounding the core part; and a firing step of molding and heating a blend containing the fired product including lump particles and a sintering aid to obtain the boron nitride sintered body having a porous structure and including lump particles of boron nitride.

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 producing a ceramic matrix composite component is disclosed. The method includes providing a plurality of first ceramic fiber plies including a plurality of interconnected tows and a plurality of first pores positioned between adjacent tows. The method includes applying a plurality of first ceramic particles within the plurality of first pores. Next, the method includes applying a plurality of second ceramic fiber plies onto an outer surface of the plurality of first ceramic fiber plies. The second ceramic fiber plies include a plurality of interconnected tows and a plurality of second pores positioned between adjacent tows. The method then includes applying a plurality of second ceramic particles within the plurality of second pores. Further, the plurality of second ceramic particles are larger than the plurality of first ceramic particles. Lastly, the method includes densifying the ceramic matrix composite preform to form the ceramic matrix composite component.

Disclosed herein is a ceramic matrix composite comprising a preform comprising a plurality of plies; a ceramic matrix encompassing the plies and distributed through the plies; and thermally conducting particles distributed through the ceramic matrix. Disclosed herein is a method comprising distributing thermally conducting particles between plies in a preform; infiltrating chemical vapors of a ceramic precursor into the plies; and reacting the ceramic precursor to form a matrix.

A low-cost, durable silicon carbide member for a plasma processing apparatus. The silicon carbide member for a plasma processing apparatus can be obtained by processing a sintered body which is produced with a method in which metal impurity is reduced to more than 20 ppm and 70 ppm or less, and an α-structure silicon carbide power having an average particle diameter of 0.3 to 3 μm and including 50 ppm or less of an Al impurity is mixed with 0.5 to 5 weight parts of a B.sub.4C sintering aid, or with a sintering aid comprising Al.sub.2O.sub.3 and Y.sub.2O.sub.3 with total amount of 3 to 15 weight parts, and then a mixture of the α-structure silicon carbide power with the sintering aid is sintered in an argon atmosphere furnace or a high-frequency induction heating furnace.

The disclosure describes techniques for infiltrating a porous preform with a slurry to form an infiltrated-preform, where the slurry includes a plurality of solid particles, where the plurality of solid particles include a plurality of fine ceramic particles defining an average fine particle diameter, a plurality of coarse ceramic particles defining an average coarse particle diameter, and a plurality of diamond particles, where the average fine particle diameter is less than the average coarse particle diameter, and infiltrating the infiltrated-preform with a molten metal infiltrant to form a ceramic matrix composite (CMC) article.

A shock absorbing member 50 having a ceramic bonded body 15 having: a plurality of first sheet-like members 5 each having a ceramic containing 60 mass % or more of boron carbide and each having a thickness of 0.1 to 50 mm; and a bonding layer arranged between the first sheet-like members 5 adjacent to each other, the bonding layer bonding surfaces to be bonded facing each other of the first sheet-like members adjacent to each other, wherein the bonding layer has a bonding material containing at least one metal selected from the group consisting of aluminum, copper, silver, and gold.

A refractory material contains: 40 mass % or more of MgO; 4 to 30 mass % of a free carbon component; and one or more of B.sub.2O.sub.3, P.sub.2O.sub.5, SiO.sub.2 and TiO.sub.2, in a total amount of 0.3 to 3 mass %, with the remainder being at least one other type of additional refractory component. A void layer exists in an interface between a carbon-containing matrix microstructure residing at least on opposite sides of a maximum-size one of a plurality of MgO-containing particles in the refractory material, and the maximum-size MgO-containing particle. A sum of respective thicknesses of the void layer at two positions on the opposite sides is 0.2 to 3.0% of a ratio with respect to particle size of the maximum-size MgO-containing particle. An inorganic compound of MgO and the one or more of B.sub.2O.sub.3, P.sub.2O.sub.5, SiO.sub.2 and TiO.sub.2 exists entirety or partially in a surface of each of the MgO-containing particles.

An armor component and manufacturing thereof which includes a ceramic hard material, where the hard material has a bulk density that is lower than 3.5 g/cm.sup.3 and includes grains of ceramic material having a Vickers hardness that is higher than 15 GPa, bonded by an bonding matrix, the bonding matrix representing between 20 and 80% by weight of the constituent hard material of the ceramic body, and including alumina, silicon nitride and TiC.sub.xN.sub.1-x crystalline phases, wherein x is included between 0 and 1.

A method for forming in situ a boron nitride reaction product locally on a reinforcement phase of a ceramic matrix composite material includes the steps of providing a ceramic matrix composite material having a fiber reinforcement material; and forming in situ a layer of boron nitride on the fiber reinforcement material.