A ceramic joined body (1) includes: a pair of ceramic plates (2,3) that include a conductive material; and a conductive layer (4) and an insulating layer (5) that are interposed between the pair of ceramic plates (2, 3), a porosity at an interface between the pair of ceramic plates (2, 3) and the insulating layer (5) is 4% or less, and a ratio of an average primary particle diameter of an insulating material which forms the insulating layer (5) to an average primary particle diameter of an insulating material which forms the ceramic plates (2, 3) is more than 1.

An automated preparation method of a SiC.sub.f/SiC composite flame tube, comprising the following steps: preparing an interface layer for a SiC fiber by a chemical vapor infiltration process, and obtaining the SiC fiber with a continuous interface layer; laying a unidirectional tape on the SiC fiber with the continuous interface layer and winding the SiC fiber with the continuous interface layer to form and obtaining a preform of a net size molding according to a fiber volume and a fiber orientation obtained in a simulation calculation; and adopting a reactive melt infiltration process and the chemical vapor infiltration process successively for a densification and obtaining a high-density SiC.sub.f/SiC composite flame tube in a full intelligent way. The SiC.sub.f/SiC composite flame tube prepared by the present disclosure not only has a high temperature resistance, but also has a low thermal expansion coefficient, high thermal conductivity and high thermal shock resistance.

An automated preparation method of a SiC.sub.f/SiC composite flame tube, comprising the following steps: preparing an interface layer for a SiC fiber by a chemical vapor infiltration process, and obtaining the SiC fiber with a continuous interface layer; laying a unidirectional tape on the SiC fiber with the continuous interface layer and winding the SiC fiber with the continuous interface layer to form and obtaining a preform of a net size molding according to a fiber volume and a fiber orientation obtained in a simulation calculation; and adopting a reactive melt infiltration process and the chemical vapor infiltration process successively for a densification and obtaining a high-density SiC.sub.f/SiC composite flame tube in a full intelligent way. The SiC.sub.f/SiC composite flame tube prepared by the present disclosure not only has a high temperature resistance, but also has a low thermal expansion coefficient, high thermal conductivity and high thermal shock resistance.

A chamber component comprises a body and a plasma sprayed ceramic coating on the body. The plasma sprayed ceramic coating is applied using a method that includes feeding powder comprising a yttrium oxide containing solid solution into a plasma spraying system, wherein the powder comprises a majority of donut-shaped particles, each of the donut-shaped particles having a spherical body with indentations on opposite sides of the spherical body. The method further includes plasma spray coating the body to apply a ceramic coating onto the body, wherein the ceramic coating comprises the yttrium oxide containing solid solution, wherein the donut-shaped particles cause the ceramic coating to have an improved morphology and a decreased porosity as compared to powder particles of other shapes, wherein the improved surface morphology comprises a reduced amount of surface nodules.

A chamber component comprises a body and a plasma sprayed ceramic coating on the body. The plasma sprayed ceramic coating is applied using a method that includes feeding powder comprising a yttrium oxide containing solid solution into a plasma spraying system, wherein the powder comprises a majority of donut-shaped particles, each of the donut-shaped particles having a spherical body with indentations on opposite sides of the spherical body. The method further includes plasma spray coating the body to apply a ceramic coating onto the body, wherein the ceramic coating comprises the yttrium oxide containing solid solution, wherein the donut-shaped particles cause the ceramic coating to have an improved morphology and a decreased porosity as compared to powder particles of other shapes, wherein the improved surface morphology comprises a reduced amount of surface nodules.

A method for forming an oxidation protection system on a composite structure is provided, which may comprise applying a ceramic layer slurry to the composite structure, wherein the ceramic layer slurry may comprise aluminum and silicon in a solvent or carrier fluid; heating the composite structure to form a ceramic layer on the composite structure, wherein the ceramic layer may comprise aluminum nitride; applying a sealing slurry to the composite structure, wherein the sealing slurry may comprise a sealing pre-slurry composition and a sealing carrier fluid, wherein the sealing pre-slurry composition may comprise a sealing phosphate glass composition; and/or heating the composite structure to form a sealing layer on the composite structure.

A method for forming an oxidation protection system on a composite structure is provided, which may comprise applying a ceramic layer slurry to the composite structure, wherein the ceramic layer slurry may comprise aluminum and silicon in a solvent or carrier fluid; heating the composite structure to form a ceramic layer on the composite structure, wherein the ceramic layer may comprise aluminum nitride; applying a sealing slurry to the composite structure, wherein the sealing slurry may comprise a sealing pre-slurry composition and a sealing carrier fluid, wherein the sealing pre-slurry composition may comprise a sealing phosphate glass composition; and/or heating the composite structure to form a sealing layer on the composite structure.

A method for fabricating multi-layer ceramic broadband radome includes thermal-spraying layers of coating materials on the radome. The assembled structure exhibits tuned RF transparency response depending on the thickness and the dielectric constant of the deposited layers. Sub-micron thick ceramic layers, which are essential for broadband performance and hard to produce due to their fragile nature, can be deposited on big and complex objects by a fast and automated process.

A method for fabricating multi-layer ceramic broadband radome includes thermal-spraying layers of coating materials on the radome. The assembled structure exhibits tuned RF transparency response depending on the thickness and the dielectric constant of the deposited layers. Sub-micron thick ceramic layers, which are essential for broadband performance and hard to produce due to their fragile nature, can be deposited on big and complex objects by a fast and automated process.

To form, on a ceramic member or a metal member, a thermal spray ceramic coating film which achieves both the quality of a ceramic coating film and gas barrier property, and with which a composite oxide having a melting point lower than the ambient temperature will not form when used as a coating film on a ceramic member or a metal member constituting a glass article manufacturing apparatus. A ceramic coating film-provided member comprising a ceramic member or a metal member and a thermal spray ceramic coating film formed on at least a part of the surface of the ceramic member or the metal member, wherein the thermal spray ceramic coating film contains Al.sub.2O.sub.3 and 12CaO.7Al.sub.2O.sub.3, and the weight ratio of CaO to Al.sub.2O.sub.3 (CaO/Al.sub.2O.sub.3) is more than 0.11 to 0.50.