Provided is a SiC-coated carbon composite material including a graphite base material and a CVD-SiC coating covering the graphite base material. A porosity of a core part of the graphite base material is 12 to 20%, and a SiC-infiltrated layer extending from the CVD-SiC coating is included in a periphery of the core part of the graphite base material. The SiC-infiltrated layer is constituted of a plurality of regions arranged such that Si content becomes smaller stepwise in an order from a first surface on the CVD-SiC coating side toward a second surface on the graphite base material side.

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.

A coating method includes depositing a slurry including a coarsely particulate ceramic and a finely particulate ceramic on a base material configured with an oxide-based ceramics matrix composite such that a proportion of coarse particles decreases towards a surface of the base material; forming a bond coating by performing a heat treatment on the base material on which the slurry has been deposited; and forming a top coating by thermally spraying a ceramic onto the bond coating. The oxide-based ceramics matrix composite is an alumina silica type oxide-based ceramics matrix composite. The coarsely particulate ceramic and the finely particulate ceramic are alumina-based powder.

Disclosed is a composite gypsum board comprising a board core and a concentrated layer, as well as related methods of preparing board and slurries. The board core and the concentrated layer both are formed from water and stucco. The concentrated layer is designed to have higher density and/or nail pull than the core. The concentrated layer is further formed from a polysaccharide that forms a complex with calcium ions, e.g., an alginate compound such as sodium alginate. In some embodiments, the concentrated layer is formed from an enhancing additive to enhance strength therein, while the core is formed without using enhancing additive or less enhancing additive than used in forming the board core.

A method for forming cement-based cementitious material includes: pouring a cement paste into a mold; applying an electrical current to the cement paste to perform an electro-osmotic reaction; and transferring the reacted cement paste into a water tank for curing, thereby obtaining a functionally graded cement-based cementitious material. A pair of electrodes is placed in the mold and connected to an external power source. The compressive strength of the functionally graded cement-based cementitious material in the middle is lower than that at either of both ends.

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.

A coating method includes depositing a slurry including a coarsely particulate ceramic and a finely particulate ceramic on a base material configured with an oxide-based ceramics matrix composite such that a proportion of coarse particles decreases towards a surface of the base material; forming a bond coating by performing a heat treatment on the base material on which the slurry has been deposited; and forming a top coating by thermally spraying a ceramic onto the bond coating. The oxide-based ceramics matrix composite is an alumina silica type oxide-based ceramics matrix composite. The coarsely particulate ceramic and the finely particulate ceramic are alumina-based powder.

The present invention relates to fiber cement products comprising an inner core material, which inner core material is covered by at least one outer surface layer, characterized in that: —said inner core material has a density of between about 0.4 and about 0.9 g/cm.sup.3 inclusive, and at least comprises cement and between 1 wt % and 70 wt % (with respect to the total dry weight of said inner core material) of a lightweight filler, and—said at least one outer surface layer has a density of between about 0.9 and about 1.4 g/cm.sup.3 inclusive, and at least comprises fibers and cement.

The present invention relates to fiber cement flooring products. In particular, the present invention provides fiber cement flooring products, at least comprising cement and fibers, characterized in that these fiber cement flooring products comprise amorphous silica in an amount of between about 2 weight % and about 15 weight % compared to the total dry weight of the fiber cement composition of said fiber cement flooring product. The present invention further relates to methods for the production of such fiber cement flooring products as well as uses of such fiber cement flooring products in the building industry. The present invention further relates to fiber cement formulations and fiber cement materials, which are suitable for the production of fiber cement products for flooring applications.