The invention relates to a grain for production of a refractory product, to the use of such grains, to a refractory product, to a process for producing a refractory product and to a refractory product produced thereby.

An improved, accident tolerant fuel for use in light water and lead fast reactors is described. The fuel includes a ceramic cladding, such as a multi-layered silicon carbide cladding, and fuel pellets formed from U.sup.15N and from 100 to 10000 ppm of a boron-containing integral fuel burnable absorber, such as UB.sub.2 or ZrB.sub.2.

A sintered material includes a first material and a second material, wherein the first material is partially stabilized ZrO.sub.2 in which 1 to 90 volume % of Al.sub.2O.sub.3 is dispersed in crystal grain boundaries or crystal grains, the Al.sub.2O.sub.3 is a grain having a grain size of less than or equal to 1 m, and the second material is at least one compound selected from a group consisting of a carbide, a nitride, and a carbonitride, and 5 to 95 volume % of the second material is included in the sintered material.

Disclosed is a composition having nanoparticles or particles of a refractory metal, a refractory metal hydride, a refractory metal carbide, a refractory metal nitride, or a refractory metal boride, an organic compound consisting of carbon and hydrogen, and a nitrogenous compound consisting of carbon, nitrogen, and hydrogen. The composition, optionally containing the nitrogenous compound, is milled, cured to form a thermoset, compacted into a geometric shape, and heated in a nitrogen atmosphere at a temperature that forms a nanoparticle composition comprising nanoparticles of metal nitride and optionally metal carbide. The nanoparticles have a uniform distribution of the nitride or carbide.

A thermoelectric composite material includes MXene inserted at a boundary of a crystal grain consisting of a thermoelectric material. Accordingly, the thermoelectric composite material may have a reduced thermal conductivity and an increased electrical conductivity. Furthermore, a mechanical property of the thermoelectric composite material may be improved. Thus, the thermoelectric composite material may improve a thermoelectric ability of a thermoelectric module.

A long-term ablation-resistant nitrogen-containing carbide ultra-high temperature ceramic with an ultra-high melting point is prepared as follows: preparing the HfC powder and the HfN powder according to a mass ratio of HfC:HfN=(1-7):1; uniformly mixing the HfC powder and the HfN powder with the carbon powder and the carbon nitride powder to obtain a mixed powder, wherein the amount of the carbon powder and the amount of the carbon nitride powder do not exceed 8.0 wt. % and 5.0 wt. %, respectively, of the mixed powder mass; and performing spark plasma sintering on the mixed powder to produce the ceramic with the ultra-high melting point, a density ?98%, and a uniform C/N content distribution. The ultra-high temperature ceramic is suitable for ultra-high temperature ablation-resistant protection at ?3000? C. The ceramic maintains a close to zero ablation rate and a continuously stable oxidation-resistant protective structure after ablation for 300 s.

An improved, accident tolerant fuel for use in light water and lead fast reactors is described. The fuel includes a ceramic cladding, such as a multi-layered silicon carbide cladding, and fuel pellets formed from U.sup.15N and from 100 to 10000 ppm of a boron-containing integral fuel burnable absorber, such as UB.sub.2 or ZrB.sub.2.

A composition having nanoparticles of a refractory-metal carbide or refractory-metal nitride and a carbonaceous matrix. The composition is not in the form of a powder. A composition comprising a metal component 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 with 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 carbide or refractory-metal nitride and a carbonaceous matrix. The composition is not in the form of a powder. A composition comprising a metal component 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 with an organic compound having a char yield of at least 60% by weight to form a precursor mixture.

Scratch-resistant coatings, especially for cooktops, and substrates or products having said scratch-resistant coatings and methods for the production thereof are described herein. More particularly, scratch-resistant coatings obtained via sol-gel approach and coated substrates having thereon a hard material layer comprising metal nitride(s) and/or metal oxynitride complexes are described, as well as the manufacturing thereof.