A porous refractory in the K.sub.2O—SiO.sub.2—B.sub.2O.sub.3 system is formed by chemical direct foaming by heating to over 600° C., resulting in adherent black or white foam. The foam can function as highly porous thermal insulation, a high or low thermal emissivity surface, as a sealant for deteriorated refractory surfaces, as a filler for pockmarks/holes/gaps or as a bonding agent for parts with large gaps between them.

The invention discloses a biologically active zirconia denture has a gradient structure, the gradient structure consisting of a biomimetic nano-gradient biologically active outer surface layer, the nano-gradient outer surface layer is composed of zirconia nanocrystals and a plurality of nanopores penetrating gradiently through the layer, a micron-gradient biocompatible inner layer, the micron-gradient inner surface layer is composed of zirconia microncrystals and a plurality of micronpores penetrating gradiently through the layer, a dense micron-gradient biocompatible matrix structure, a uniform gradient transition is formed at the interface between the nano-gradient outer layer and the micron-gradient inner layer, and the micron-gradient inner layer and the matrix. The invention has the advantages of high strength, high toughness, low friction coefficient, low abrasion to the teeth, good biocompatibility and biological activity.

The invention discloses a biologically active zirconia denture has a gradient structure, the gradient structure consisting of a biomimetic nano-gradient biologically active outer surface layer, the nano-gradient outer surface layer is composed of zirconia nanocrystals and a plurality of nanopores penetrating gradiently through the layer, a micron-gradient biocompatible inner layer, the micron-gradient inner surface layer is composed of zirconia microncrystals and a plurality of micronpores penetrating gradiently through the layer, a dense micron-gradient biocompatible matrix structure, a uniform gradient transition is formed at the interface between the nano-gradient outer layer and the micron-gradient inner layer, and the micron-gradient inner layer and the matrix. The invention has the advantages of high strength, high toughness, low friction coefficient, low abrasion to the teeth, good biocompatibility and biological activity.

A sintered body includes a ceramic substrate including sintered oxide particles, a through-hole formed in the ceramic substrate such that the side surfaces of the oxide particles exposed from an inner wall of the through-hole form a flat surface, and a porous body disposed in the through-hole, the porous body including spherical oxide ceramic particles and a mixed oxide configured to bind the spherical oxide ceramic particles.

A sintered body includes a ceramic substrate including sintered oxide particles, a through-hole formed in the ceramic substrate such that the side surfaces of the oxide particles exposed from an inner wall of the through-hole form a flat surface, and a porous body disposed in the through-hole, the porous body including spherical oxide ceramic particles and a mixed oxide configured to bind the spherical oxide ceramic particles.

A method of producing a ceramic matrix composite including a protective ceramic coating thereon comprises applying a surface slurry onto an outer surface of an impregnated fiber preform. The surface slurry includes particulate ceramic solids dispersed in a flowable preceramic polymer comprising silicon, and the impregnated fiber preform comprises a framework of ceramic fibers loaded with particulate matter. The flowable preceramic polymer is cured, thereby forming on the outer surface a composite layer comprising a cured preceramic polymer with the particulate ceramic solids dispersed therein. The cured preceramic polymer is then pyrolyzed to form a porous ceramic layer comprising silicon carbide, and the impregnated fiber preform and the porous ceramic layer are infiltrated with a molten material comprising silicon. After infiltration, the molten material is cooled to form a ceramic matrix composite body with a protective ceramic coating thereon.

A method of producing a ceramic matrix composite including a protective ceramic coating thereon comprises applying a surface slurry onto an outer surface of an impregnated fiber preform. The surface slurry includes particulate ceramic solids dispersed in a flowable preceramic polymer comprising silicon, and the impregnated fiber preform comprises a framework of ceramic fibers loaded with particulate matter. The flowable preceramic polymer is cured, thereby forming on the outer surface a composite layer comprising a cured preceramic polymer with the particulate ceramic solids dispersed therein. The cured preceramic polymer is then pyrolyzed to form a porous ceramic layer comprising silicon carbide, and the impregnated fiber preform and the porous ceramic layer are infiltrated with a molten material comprising silicon. After infiltration, the molten material is cooled to form a ceramic matrix composite body with a protective ceramic coating thereon.

An erosion and CMAS resistant coating arranged on an EBC coated substrate includes at least one porous vertically cracked (PVC) coating layer providing CTE mitigation and being disposed over the EBC coated substrate. At least one dense vertically cracked (DVC) erosion and CMAS resistant coating layer is deposited over the at least one PVC coating layer.

An erosion and CMAS resistant coating arranged on an EBC coated substrate includes at least one porous vertically cracked (PVC) coating layer providing CTE mitigation and being disposed over the EBC coated substrate. At least one dense vertically cracked (DVC) erosion and CMAS resistant coating layer is deposited over the at least one PVC coating layer.

A shell and a method for processing the shell are provided. The method includes: coating a sol prepared in advance on an inner surface of a ceramic shell prepared in advance; sintering the ceramic shell coated with the sol by using a sintering process, and forming a transition layer having nano-sized micro-pores on the inner surface of the ceramic shell.