A process for preparing a composite material comprising an electride compound and an additive, said process comprising (i) providing a composition comprising the additive and a precursor compound of the electride compound, wherein the precursor compound comprises an oxidic compound of the garnet group, and wherein the additive has a boiling temperature which is higher than the melting temperature of the precursor compound; (ii) heating the composition provided in (i) under plasma forming conditions in a gas atmosphere to a temperature above the Httig temperature of the precursor compound and below the boiling temperature of the additive, obtaining the composite material.

A high strength ceramic body for use in a regenerative burner media bed, comprising a generally spherical refractory portion and a plurality of irregular aggregate portions distributed randomly throughout the generally spherical portion. The aggregate portions are selected from the group comprising tabular alumina, white fused alumina, mullite, chamotte, and combinations thereof. The generally spherical portion has a porosity of less than 1 percent and is more than 99.5 weight percent alumina.

It is an object to provide a cubic boron nitride polycrystalline material excellent in toughness. A cubic boron nitride polycrystalline material containing fine cubic boron nitride which is granular, has a maximum grain size not greater than 100 nm, and has an average grain size not greater than 70 nm and at least one of plate-shaped cubic boron nitride in a form of a plate having an average major radius not smaller than 50 nm and not greater than 10000 nm and coarse cubic boron nitride which is granular, has a minimum grain size exceeding 100 nm, and has an average grain size not greater than 1000 nm is provided.

A high strength ceramic body for use in a regenerative burner media bed, comprising a generally spherical refractory portion and a plurality of irregular aggregate portions distributed randomly throughout the generally spherical portion. The aggregate portions are selected from the group comprising tabular alumina, white fused alumina, mullite, chamotte, and combinations thereof. The generally spherical portion has a porosity of less than 1 percent and is more than 99.5 weight percent alumina.

A process for producing a process for producing a LnM.sub.2Cu.sub.3O.sub.x high-temperature superconductive powder, the process comprising: i) providing an aqueous solution of Ln, M and Cu and at least one mineral acid; ii) adding at least one sequestrating agent and, optionally, at least one dispersant to the solution to form a precipitate; iii) recovering the precipitate from the solution; and iv) heating the precipitate in a flow of oxygen to form the LnM.sub.2Cu.sub.3O.sub.x powder, wherein Ln is a rare earth element, preferably Y, Ce, Dy, Er, Gd, La, Nd, Pr, Sm, Sc, Yb, or a mixture of two or more thereof, and wherein M is selected from Ca, Sr, and Ba.

A porous plate-shaped filler of the present invention is a plate shape having an aspect ratio of 3 or more, a surface shape is one of a round shape, an oval and a round-corner polygonal shape, and its minimum length is from 0.1 to 50 m. Furthermore, a sectional shape is one of an arch shape, an elliptic shape, and a quadrangular shape in which at least a part of corners is rounded. Consequently, it is possible to obtain the heat insulation film in which the porous plate-shaped fillers 1 are easy to be laminated and the heat insulation effect improves.

A method includes: supplying sources or nanoparticles of any one or two or more combinations selected from a group which consists of a carbon source, a doping source, a doped element containing carbon source, and a waste plastic source into a high-temperature and high-pressure closed autoclave, completely closing the high-temperature and high-pressure closed autoclave, and forming a nanoparticle-carbon core-shell structure by a single process by coating a carbon layer on the surface of the nanoparticles or forming a core-shell structure of nanoparticle-doped carbon by the single process by coating a carbon layer doped with the doped element on the surface of the nanoparticles under pressure self-generated in the autoclave and a reaction temperature in the range of 500 to 850 C. by heating the autoclave.

A magnetizable abrasive particle comprises a ceramic body having an outer surface and a magnetizable layer disposed on a portion, but not the entirety, of the outer surface. The ceramic body comprises a platelet having two opposed major facets connected to each other by a plurality of side facets. The magnetizable layer completely covers one of the two opposed major facets, and the magnetizable layer has a magnetic dipole oriented perpendicular or parallel to the facet which it completely covers. A plurality of the magnetizable abrasive particles, and abrasive articles including them are also disclosed. Methods of making the foregoing are also disclosed.

A transition metal catalyst free polycrystalline diamond compact having enhanced thermal stability is disclosed herein. The diamond compact may be attached to a hard metal substrate. The polycrystalline diamond body includes a plurality of diamond grains bonded to adjacent diamond grains by diamond-to-diamond bonds. Sintering of the PCD and the formation of diamond-to-diamond bonding is achieved by transforming graphene treated diamond crystals that are blended with non-metal additives at high pressure and high temperature into a diamond compact that is free of transition metal catalysts. Non-metal additives include vitreous and other non-equilibrium forms of carbon as well as Sr-, K- and Ca-containing carbon sources.

Disclosed are: damage-resistant ECMCs that need to work and remain elastic between minus 120 C. and positive 300 C.; ECMCs that need to be able to contain a flame of 1900 C. for more than 90 minutes; and composite structures, especially highly stressed structures. One of the characteristic problems of ceramic matrices is their fragility. Indeed, when a fracture starts, it propagates easily in the matrix. Disclosed are elastic ceramic matrix composites (ECMCs), for which: the ceramic matrix is split into solid ceramic microdomains (CMDs); the CMDs are connected to one another by a dense network of elastic microelements (EMEs); and the bonds between the EMEs and the CMDs are strong chemical bonds, preferably covalent.