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.

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.

Systems and methods for forming an oxidation protection system on a composite structure are provided. In various embodiments, an oxidation protection system disposed on a substrate may comprise a boron-silicon-glass layer formed directly on the composite structure. The boron-silicon-glass layer may comprise a boron compound, a silicon compound, and a glass compound.

Disclosed are an organic binder-based coating; a composite gypsum board containing face and back cover sheets, an outside surface of the back cover sheet bearing the coating; and a method of preparing composite board where the back cover sheet contains the coating on its outer surface. The coating is formed from a composition comprising an alkaline silicate, a solid filler, and optionally, a borate. An enhancing layer can also be applied to the back cover sheet.

Disclosed are an organic binder-based coating; a composite gypsum board containing face and back cover sheets, an outside surface of the back cover sheet bearing the coating; and a method of preparing composite board where the back cover sheet contains the coating on its outer surface. The coating is formed from a composition comprising an alkaline silicate, a solid filler, and optionally, a borate. An enhancing layer can also be applied to the back cover sheet.

A ceramic component is provided that includes a silicon-based layer comprising a silicon-containing material (e.g., a silicon metal and/or a silicide) and a boron-doped refractory compound, such as about 0.001% to about 85% by volume of the boron-doped refractory compound (e.g., about 1% to about 60% by volume of the boron-doped refractory compound). A coated component is also provided that includes a CMC component defining a surface; a bond coating directly on the surface of the CMC component, with the bond coating comprises a silicon-containing material and a boron-doped refractory compound (e.g., about 0.1% to about 25% of the boron-doped refractory compound); a thermally grown oxide layer on the bond coating; and an environmental barrier coating on the thermally grown oxide layer.

A ceramic component is provided that includes a silicon-based layer comprising a silicon-containing material (e.g., a silicon metal and/or a silicide) and a boron-doped refractory compound, such as about 0.001% to about 85% by volume of the boron-doped refractory compound (e.g., about 1% to about 60% by volume of the boron-doped refractory compound). A coated component is also provided that includes a CMC component defining a surface; a bond coating directly on the surface of the CMC component, with the bond coating comprises a silicon-containing material and a boron-doped refractory compound (e.g., about 0.1% to about 25% of the boron-doped refractory compound); a thermally grown oxide layer on the bond coating; and an environmental barrier coating on the thermally grown oxide layer.

A ceramic matrix composite (CMC) component includes at least one seal surface, the at least one seal surface disposed adjacent an interfacing surface for providing a seal therebetween; and a coating disposed on the seal surface. The coating includes an aluminum oxide and/or a silicon dioxide.

A ceramic matrix composite (CMC) component includes at least one seal surface, the at least one seal surface disposed adjacent an interfacing surface for providing a seal therebetween; and a coating disposed on the seal surface. The coating includes an aluminum oxide and/or a silicon dioxide.

A coating includes: at least 34.9 percent by mass silicon dioxide; at least 9.1 percent by mass aluminum oxide; and at least 16.1 percent by mass yttrium oxide.