A mould for manufacturing a packing member from a liquid ceramic composition. The mould including a first part and a second part, in which the first and/or second mould parts are resiliently deformable and the first part and/or the second part include a plurality of open mould cavities. The first and second parts are operable to engage to form closed mould cavities, and the mould is operable to be moved from an open position in which the first and second parts are partially spaced by the deformation of a mould part and in which position mould cavities are open, to a partially closed position by reducing the deformation of the mould part and in which position some of the mould cavities are closed, and then to a closed position by further reducing the deformation of the mould part and in which position the first and second parts are engaged such that the mould cavities are closed.

An alumina-ceramic-based electrical insulator, to a method for producing the insulator, and to a vacuum tube includes the insulator. The electrical insulator is for insulating two electrodes of a vacuum tube through which a charged particle beam flows, the electrical insulator being formed of an alumina-based ceramic. The ceramic comprises a vitreous phase of between 2% and 8% by weight into which at least one metal oxide is diffused from a face of the electrical insulator.

An alumina-ceramic-based electrical insulator, to a method for producing the insulator, and to a vacuum tube includes the insulator. The electrical insulator is for insulating two electrodes of a vacuum tube through which a charged particle beam flows, the electrical insulator being formed of an alumina-based ceramic. The ceramic comprises a vitreous phase of between 2% and 8% by weight into which at least one metal oxide is diffused from a face of the electrical insulator.

Process for treating a porous dental zirconia block with a coloring solution, the process comprising the steps of providing a porous dental zirconia block having two opposing surfaces, surface U and surface L, treating the upper surface U of the porous dental zirconia block with a coloring solution A.sub.1, wherein the coloring solution is provided with a volume VA.sub.1, turning the porous dental zirconia block around, treating the lower surface L with a coloring solution A.sub.2 which is provided with a volume VA.sub.2. wherein the coloring solutions A.sub.1 and A.sub.2 comprise a solvent and coloring ions, wherein the volume of at least one of the coloring solutions A.sub.1 or A.sub.2 is applied in portions, wherein the following condition is met: Vo=ΣV.sub.AX, with x≥2, with Vo being the overall amount of coloring solution used to infiltrate the porous dental zirconia block.

Process for treating a porous dental zirconia block with a coloring solution, the process comprising the steps of providing a porous dental zirconia block having two opposing surfaces, surface U and surface L, treating the upper surface U of the porous dental zirconia block with a coloring solution A.sub.1, wherein the coloring solution is provided with a volume VA.sub.1, turning the porous dental zirconia block around, treating the lower surface L with a coloring solution A.sub.2 which is provided with a volume VA.sub.2. wherein the coloring solutions A.sub.1 and A.sub.2 comprise a solvent and coloring ions, wherein the volume of at least one of the coloring solutions A.sub.1 or A.sub.2 is applied in portions, wherein the following condition is met: Vo=ΣV.sub.AX, with x≥2, with Vo being the overall amount of coloring solution used to infiltrate the porous dental zirconia block.

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 of applying a protective coating to a substrate includes the steps of: providing a turbine engine component substrate formed of a ceramic matrix composite material, forming an environmental barrier coating layer including a rare earth disilicate material directly on the substrate, treating an outer surface of the environmental barrier coating layer to form a thermal barrier coating layer including a porous rare earth monociliate material directly on the environmental barrier coating layer. The step of treating the outer surface is performed using a thermal process consisting of the application of heat or a chemical-thermal process consisting of the application of heat and a chemical. The method further includes infiltrating at least a portion of the pores with a metal solution or suspension.

A method of applying a protective coating to a substrate includes the steps of: providing a turbine engine component substrate formed of a ceramic matrix composite material, forming an environmental barrier coating layer including a rare earth disilicate material directly on the substrate, treating an outer surface of the environmental barrier coating layer to form a thermal barrier coating layer including a porous rare earth monociliate material directly on the environmental barrier coating layer. The step of treating the outer surface is performed using a thermal process consisting of the application of heat or a chemical-thermal process consisting of the application of heat and a chemical. The method further includes infiltrating at least a portion of the pores with a metal solution or suspension.

A protective coating system includes a turbine engine component substrate formed of a ceramic matrix composite material, an environmental barrier coating layer including a rare earth disilicate material formed directly on the substrate, and a thermal barrier coating layer including a porous rare earth monosilicate material having a metal silicate material infiltrated within at least a portion of the pores formed directly on the environmental barrier coating layer.