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.

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.

A method for coating a ceramic matrix composite part with an environmental barrier, includes a) applying, to the surface of the part, a coating composition including a first powder of a rare earth silicate and a second powder including boron, the coating composition having a ratio R=[mass of the second powder]/[mass of the first powder] of between 0.1% and 5%, wherein the second powder includes a boron powder, and b) sintering the first and second powders in order to obtain the environmental barrier on the part.

A method for coating a ceramic matrix composite part with an environmental barrier, includes a) applying, to the surface of the part, a coating composition including a first powder of a rare earth silicate and a second powder including boron, the coating composition having a ratio R=[mass of the second powder]/[mass of the first powder] of between 0.1% and 5%, wherein the second powder includes a boron powder, and b) sintering the first and second powders in order to obtain the environmental barrier on the part.

Methods for forming a sintered bond coat (64) on a silicon-based substrate (14) and articles (50) formed by the methods are disclosed. The methods include applying a bond coat slurry on the silicon-based substrate (14), drying the bond coat slurry on the silicon-based substrate to form a dried bond coat (44), and sintering the dried bond coat (44) in an oxidizing atmosphere to form a sintered bond coat (64) on the silicon-based substrate (14). The bond coat slurry includes a bond coat patching material in a bond coat fluid carrier. The articles (50) include a silicon-based substrate (14), a sintered bond coat (64) formed on the silicon-based substrate (14), and a sintered environmental barrier coating (EBC) (66) formed on the sintered bond coat (64). The sintered bond coat (64) includes a silicon-based phase and an oxide of the silicon-based phase.

Methods for forming a sintered bond coat (64) on a silicon-based substrate (14) and articles (50) formed by the methods are disclosed. The methods include applying a bond coat slurry on the silicon-based substrate (14), drying the bond coat slurry on the silicon-based substrate to form a dried bond coat (44), and sintering the dried bond coat (44) in an oxidizing atmosphere to form a sintered bond coat (64) on the silicon-based substrate (14). The bond coat slurry includes a bond coat patching material in a bond coat fluid carrier. The articles (50) include a silicon-based substrate (14), a sintered bond coat (64) formed on the silicon-based substrate (14), and a sintered environmental barrier coating (EBC) (66) formed on the sintered bond coat (64). The sintered bond coat (64) includes a silicon-based phase and an oxide of the silicon-based phase.

Provided is a wear resistant, sintered body made of a binderless carbide, cermet or cemented carbide, e.g., WC, W2C and/or eta-phase, with a grain size less than 6.0 ?m, and less than 6% binder phase (e.g., CoNiFe). At least some working surfaces of the sintered body are surface treated with a boron yielding method including applying a low viscosity liquid medium having boron or aluminum content and heating at 1200? C. to 1450? C. under a pressure less than atmospheric pressure or a hydrogen containing atmosphere to from a hardness gradient with an increased hardness of the treated working surfaces of at least 50 to 200 HV5 and favorable compressive stresses in a surface zone that gives a tougher working surfaces of the boronized sintered bodies.

Provided is a wear resistant, sintered body made of a binderless carbide, cermet or cemented carbide, e.g., WC, W2C and/or eta-phase, with a grain size less than 6.0 ?m, and less than 6% binder phase (e.g., CoNiFe). At least some working surfaces of the sintered body are surface treated with a boron yielding method including applying a low viscosity liquid medium having boron or aluminum content and heating at 1200? C. to 1450? C. under a pressure less than atmospheric pressure or a hydrogen containing atmosphere to from a hardness gradient with an increased hardness of the treated working surfaces of at least 50 to 200 HV5 and favorable compressive stresses in a surface zone that gives a tougher working surfaces of the boronized sintered bodies.

The present invention concerns compositions and methods of using the same that provide encapsulated polymer nanocomposites for efficient crack repair and monitoring of a cement-substrate interface.

The present disclosure provides methods related to infiltration of aircraft brake discs with titanium-containing compounds. In various embodiments, a method of making a self-coating carbon/carbon composite member may comprise infiltrating a carbonized fiber preform with a titanium-containing compound, drying the carbonized fiber preform, annealing the carbonized fiber preform at a third temperature, and densifying the carbonized fiber preform.