A thermal protection system (TPS) comprising a mixture of silicon carbide and SiO.sub.x that has been converted from Si that is present in a collection of diatom frustules and at least one diatom has quasi-periodic pore-to-pore separation distance d(p-p) in a selected range. Where a heat shield comprising the converted SiC/SiO.sub.x frustules receives radiation, associated with atmospheric (re)entry, a portion of this radiation is reflected so that radiation loading of the heat shield is reduced.

A copper/ceramic bonded body includes: a copper member made of copper or a copper alloy; and a ceramic member made of an aluminum nitride, wherein, the copper member and the ceramic member are bonded to each other, and a Mg solid solution layer is provided between the copper member and the ceramic member and contains Mg in a state of a solid solution in a Cu primary phase.

Embodiments of disclosure may provide a method for forming an aluminum-containing nitride ceramic matrix composite, comprising heating a green body, an aluminum-containing composition, ammonia and a mineralizer composition in a sealable container to a temperature between about 400 degrees Celsius and about 800 degrees Celsius and a pressure between about 10 MPa and about 1000 MPa, to form an aluminum-containing nitride ceramic matrix composite characterized by a phosphor-to-aluminum nitride (AlN) ratio, by volume, between about 1% and about 99%, by a porosity between about 1% and about 50%, and by a thermal conductivity between about 1 watt per meter-Kelvin and about 320 watts per meter-Kelvin. The green body comprises a phosphor powder comprising at least one phosphor composition, wherein the phosphor powder particles are characterized by a D50 diameter between about 100 nanometers and about 500 micrometers, and the green body has a porosity between about 10% and about 80%. The aluminum-containing composition has a purity, on a metals basis, between about 90% and about 99.9999%. The fraction of free volume within the sealable container contains between about 10% and about 95% of liquid ammonia prior to heating the green body, the aluminum-containing composition, ammonia and the mineralizer composition in the sealable container.

A method of fabricating a diamond compact includes functionalizing surfaces of diamond nanoparticles with fluorine; combining the functionalized diamond nanoparticles with a non-group-VIII metal to form a particle mixture; and subjecting the particle mixture to high pressure and high temperature (HPHT) conditions to form inter-granular bonds between the diamond nanoparticles. A cutting element for an earth-boring tool includes a plurality of grains of diamond material; a plurality of diamond nanoparticles bonded to the plurality of grains of diamond material; and a non-group-VIII metal fluoride disposed within interstitial spaces between the grains of diamond material and the plurality of diamond nanoparticles. The cutting element is substantially free of a metal-solvent catalyst.

Polycrystalline diamond cutters for rotary drill bits and methods of making the same are disclosed. A polycrystalline diamond compact includes a polycrystalline diamond body having a working surface, an interface surface, and a perimeter surface. The polycrystalline diamond compact also includes a substrate bonded to the polycrystalline diamond body along the interface surface. A non-diamond volume fraction of the polycrystalline diamond body is greater at the interface surface than at the working surface.

Embodiments of disclosure may provide a method for forming an aluminum-containing nitride ceramic matrix composite, comprising heating a green body, an aluminum-containing composition, ammonia and a mineralizer composition in a sealable container to a temperature between about 400 degrees Celsius and about 800 degrees Celsius and a pressure between about 10 MPa and about 1000 MPa, to form an aluminum-containing nitride ceramic matrix composite characterized by a phosphor-to-aluminum nitride (AlN) ratio, by volume, between about 1% and about 99%, by a porosity between about 1% and about 50%, and by a thermal conductivity between about 1 watt per meter-Kelvin and about 320 watts per meter-Kelvin. The green body comprises a phosphor powder comprising at least one phosphor composition, wherein the phosphor powder particles are characterized by a D50 diameter between about 100 nanometers and about 500 micrometers, and the green body has a porosity between about 10% and about 80%. The aluminum-containing composition has a purity, on a metals basis, between about 90% and about 99.9999%. The fraction of free volume within the sealable container contains between about 10% and about 95% of liquid ammonia prior to heating the green body, the aluminum-containing composition, ammonia and the mineralizer composition in the sealable container.

A method of fabricating a diamond compact includes functionalizing surfaces of diamond nanoparticles with fluorine; combining the functionalized diamond nanoparticles with a non-group-VIII metal to form a particle mixture; and subjecting the particle mixture to high pressure and high temperature (HPHT) conditions to form inter-granular bonds between the diamond nanoparticles. A cutting element for an earth-boring tool includes a plurality of grains of diamond material; a plurality of diamond nanoparticles bonded to the plurality of grains of diamond material; and a non-group-VIII metal fluoride disposed within interstitial spaces between the grains of diamond material and the plurality of diamond nanoparticles. The cutting element is substantially free of a metal-solvent catalyst.

Provided is at least one of a zirconia sintered body, a raw material powder for the zirconia sintered body, a calcined body and a method for producing the sintered body. The zirconia sintered body does not exhibit a color derived from ceria and exhibits high impact resistance. The sintered body comprises zirconia and germanium oxide, the zirconia containing a stabilizing element, wherein Y/X is 0.35 or greater, and X+Y is 4.0 or less, where X is an amount of the stabilizing element in the zirconia expressed in mol %, and Y is an amount of the germanium oxide in the zirconia expressed in mol %.

Brake disks with integrated heat sink are provided. Brake disk includes a fiber-reinforced composite material and an encapsulated heat sink material impregnated into the fiber-reinforced composite material. The encapsulated heat sink material comprises a heat sink material encapsulated within a silicon-containing encapsulation layer. Methods for manufacturing the brake disk with integrated heat sink and methods for producing the encapsulated heat sink material are also provided.

Pre-ceramic particle solutions can prepared by a Coordinated-PDC process, a Direct-PDC process or a Coordinated-Direct-PDC process. The pre-ceramic particle solution includes a polymer selected from the group consisting of (i) an organic polymer including a metal or metalloid cation, (ii) a first organometallic polymer and (iii) a second organometallic polymer including a metal or metalloid cation different from a metal in the second organometallic polymer, a plurality of particles selected from the group consisting of (a) a ceramic fuel particle and (b) a moderator particle, a dispersant, and a polymerization initiator. The pre-ceramic particle solution can be supplied to an additive manufacturing process, such as digital light projection, and made into a structure (which is pre-ceramic particle green body) that can then be debinded to form a polymer-derived ceramic sintered body. In some embodiments, the polymer-derived ceramic sintered body is a component or structure for fission reactors.