A method of manufacturing a silicon carbide (SiC) sintered body and a SiC sintered body obtained by the method are provided. The method includes: preparing a composite powder by subjecting a SiC raw material and a sintering aid raw material to mechanical alloying; and sintering the composite powder, wherein the sintering aid is at least one selected from the group consisting of an AlC-based material, an AlBC-based material, and a BC-based material. Accordingly, a SiC sintered body that can be sintered at low temperature, can be densified, and has high strength and high electrical conductivity can be prepared.

Embodiments of the invention relate to polycrystalline diamond bodies having nanoparticles disposed in a region therein, and methods of fabricating the same.

A composition having nanoparticles of a boron carbide and a carbonaceous matrix. The composition is not in the form of a powder. A composition comprising boron and an organic component. The organic component is an organic compound having a char yield of at least 60% by weight or a thermoset made from the organic compound. A method of combining boron and an organic compound having a char yield of at least 60% by weight, and heating to form boron carbide or boron nitride nanoparticles.

Ceramic matrix composite materials and a process for making said composite materials are disclosed.

A pre-impregnated composite tape is provided that includes: a matrix material; a plurality of fibers forming unidirectional arrays of tows encased within the matrix material; and a plurality of filler particles dispersed between adjacent fibers in the tape. The fibers have a mean fiber diameter of about 5 microns and about 40 microns, and are included within the tape at a volume fraction of about 15% and about 40%. The plurality of filler particles have a log-normal volumetric median particle size, such that the tape has a ratio of the log-normal volumetric median particle size to the mean fiber diameter that is about 0.05:1 to about 1:1. A method is also provided for forming a ceramic matrix composite.

A method for fabricating a ceramic material includes impregnating a porous structure with a mixture that includes a preceramic polymer and a filler. The filler includes at least one free metal. The preceramic polymer material is then rigidized to form a green body. The green body is then thermally treated to convert the rigidized preceramic polymer material into a ceramic matrix located within pores of the porous structure. The same thermal treatment or a second, further thermal treatment is used to cause the at least one free metal to move to internal porosity defined by the ceramic matrix or pores of the porous structure.

A composition having nanoparticles of a refractory-metal boride and a carbonaceous matrix. The composition is not in the form of a powder. A composition comprising a metal component, boron, and an organic component. The metal component is nanoparticles or particles of a refractory metal or a refractory-metal compound capable of decomposing into refractory metal nanoparticles. The organic component is an organic compound having a char yield of at least 60% by weight or a thermoset made from the organic compound. A method of combining particles of a refractory metal or a refractory-metal compound capable of reacting or decomposing into refractory-metal nanoparticles, boron, and an organic compound having a char yield of at least 60% by weight to form a precursor mixture. A composition having nanoparticles of a refractory-metal boride that is not in the form of a powder.

A method for fabricating a ceramic material includes impregnating a porous structure with a mixture that includes a preceramic polymer and a filler. The filler includes at least one free metal. The preceramic polymer material is then rigidized to form a green body. The green body is then thermally treated to convert the rigidized preceramic polymer material into a ceramic matrix located within pores of the porous structure. The same thermal treatment or a second, further thermal treatment is used to cause the at least one free metal to move to internal porosity defined by the ceramic matrix or pores of the porous structure.

To provide a lead-free piezoelectric material having a high and stable piezoelectric constant in a wide operating temperature range. The piezoelectric material contains a perovskite type metal oxide having the general formula (1), Mn, Mg,
(Ba.sub.1-xCa.sub.x).sub.a(Ti.sub.1-y-zSn.sub.yZr.sub.z)O.sub.3(1) (wherein x is in the range of 0.050x0.200, y is in the range of 0.010y0.040, and z is in the range of 0z0.040, provided that x0.375(y+z)+0.050, and a is in the range of 0.9925+ba1.0025+b) wherein the amount b (mol) of Mn on a metal basis per mole of the metal oxide is in the range of 0.0048b0.0400, and the Mg content on a metal basis per 100 parts by weight of the metal oxide is 0.100 parts by weight or less.

A ceramic article includes a ceramic matrix composite that has a porous reinforcement structure and a ceramic matrix within pores of the porous reinforcement structure. The ceramic matrix composite includes a surface zone comprised of an exterior surface of the ceramic matrix composite and pores that extend from the exterior surface into the ceramic matrix composite. A glaze material seals the surface zone within the pores of the surface zone and on the exterior surface of the surface zone as an exterior glaze layer on the ceramic matrix composite. The glaze material is a glass or glass-ceramic material. The ceramic matrix composite includes an interior zone under the surface zone, and the interior zone is free of any of the glaze material and has a greater porosity than the surface zone.