A wallboard product and a method of making a wallboard product are provided. The method may include providing a wallboard core. And exterior surface may be provided to the wallboard core. The exterior surface may include a magnesium compound.

An article includes a ceramic-based substrate and a barrier layer on the ceramic-based substrate. The barrier layer includes a matrix phase and gettering particles in the matrix phase. The gettering particles with an aspect ratio greater than one are aligned such that a maximum dimension of the gettering particles extends along an axis that is generally parallel to the substrate. The barrier layer includes a dispersion of diffusive particles in the matrix phase. A composite material and a method of applying a barrier layer to a substrate are also disclosed.

An article includes a ceramic-based substrate and a barrier layer on the ceramic-based substrate. The barrier layer includes a matrix phase and gettering particles in the matrix phase. The gettering particles with an aspect ratio greater than one are aligned such that a maximum dimension of the gettering particles extends along an axis that is generally parallel to the substrate. The barrier layer includes a dispersion of diffusive particles in the matrix phase. A composite material and a method of applying a barrier layer to a substrate are also disclosed.

The present invention relates to a method for manufacturing a silicon nitride substrate and, more specifically, comprises the steps of: forming a slurry by mixing silicon nitride powder, a ceramic additive, and a solvent; molding the slurry to form sheets; sandwiching at least one of the sheets between a lower plate and an upper plate to form a stacked structure; degreasing the stacked structure; and sintering the stacked structure. At least one of the lower plate and the upper plate comprises a plurality of protrusions provided on one surface thereof, and the protrusions extend in parallel to each other in one direction.

An article includes a ceramic-based substrate and a barrier layer on the ceramic-based substrate. The barrier layer includes a matrix phase and gettering particles in the matrix phase. The gettering particles with an aspect ratio greater than one are aligned such that a maximum dimension of the gettering particles extends along an axis that is generally parallel to the substrate. The barrier layer includes a dispersion of diffusive particles in the matrix phase. A composite material and a method of applying a barrier layer to a substrate are also disclosed.

An article includes a ceramic-based substrate and a barrier layer on the ceramic-based substrate. The barrier layer includes a matrix phase and gettering particles in the matrix phase. The gettering particles with an aspect ratio greater than one are aligned such that a maximum dimension of the gettering particles extends along an axis that is generally parallel to the substrate. The barrier layer includes a dispersion of diffusive particles in the matrix phase. A composite material and a method of applying a barrier layer to a substrate are also disclosed.

An example article may include a component, a substrate including a first ceramic, a joining layer between the component and the substrate, and a joint surface coating between the substrate and the joining layer. The joint surface coating may include a diffusion barrier layer including a second ceramic material, and a compliance layer including at least one of a metal or a metalloid. An example technique may include holding a first joining surface of a coated component adjacent a second joining surface of a second component. The example technique may further include heating at least one of the coated component, the second component, and a braze material, and brazing the coated component by allowing the braze material to flow in a region between the first joining surface and the second joining surface.

Disclosed is a gypsum board comprising a set gypsum core disposed between two cover sheets. The set gypsum core is formed from a slurry comprising stucco, water, and at least one pregelatinized starch having a viscosity of from about 20 cP to about 300 cP as measured according to the VMA method described herein. The starch is present in an amount of greater than 10% by weight of the stucco. In preferred embodiments, the board has good strength properties even at lower densities, such as about 31 pcf or less. Also disclosed are a related method of making a gypsum wallboard and a slurry.

Hybrid composite materials including carbon nanotube sheets and flexible ceramic materials, and methods of making the same are provided herein. In one embodiment, a method of forming a hybrid composite material is provided, the method including: placing a layer of a first flexible ceramic composite on a lay-up tooling surface; applying a sheet of a pre-preg carbon fiber reinforced polymer on the flexible ceramic composite; curing the flexible ceramic composite and the pre-preg carbon fiber reinforced polymer sheet together to form a hybrid composite material; and removing the hybrid composite material from the lay-up tooling surface, wherein the first flexible ceramic composite comprises an exterior surface of the hybrid composite material.

An environmental barrier coating system for a turbine component, including an environmental barrier layer applied to a turbine component substrate containing silicon; the environmental barrier layer comprising an oxide matrix surrounding a fiber-reinforcement structure and a self-healing phase interspersed throughout the oxide matrix; wherein the fiber-reinforcement structure comprises at least one first fiber bundle oriented along a load bearing stress direction of said turbine component substrate; wherein the fiber-reinforcement structure comprises at least one second fiber bundle oriented orthogonal to the at least one first fiber bundle orientation; wherein the fiber-reinforcement structure comprises at least one third fiber woven between the at least one first fiber bundle and the at least one second fiber bundle.