Abstract: A static chemical vapor deposition (CVD) process may be used to deposit a coating including a ?-Ni+??-Ni3Al phase constitution over a substrate. A static CVD process is performed in a closed system that may include the substrate, and coating material and an activator. The ?-Ni+??-Ni3Al coating may be modified by one or more additional elements, including, for example, Hf, Y, Zr, Ce, La, Si, Cr, Pt, or additional elements present in the substrate. A static CVD process may include co-deposition of two or more elements, and may also include sequential static CVD steps, each of which is performed in a closed system.

Abstract: A multilayer thermal barrier coating (TBC) may include a plurality of layers selected to provide properties to the multilayer TBC. For example, a multilayer TBC may include a first layer deposited over a substrate, a second layer deposited over the first layer and a third layer deposited over the second layer. The first layer may be selected to provide thermal cycling resistance, the second layer may be selected to provide low thermal conductivity and the third layer may be selected to provide at least one of erosion resistance and CMAS degradation resistance. The multilayer TBC may also include two layers, or more than three layers.

Abstract: A reinforced coating may include an oxide matrix and a reinforcement. In some embodiments, the reinforcement may include at least one of SiC and Si3N4. The reinforced coating may be deposited over a substrate, which may include a superalloy, ceramic or ceramic matrix composite (CMC). The reinforced coating may be deposited over the substrate alone or in combination with one or more additional oxide layers and/or a bond coat. The reinforced coating may be deposited using plasma spraying, physical vapor deposition, cathodic arc deposition, chemical vapor deposition, slurry dip coating, sol-gel coating, electrophoretic deposition, or another suitable deposition process.

Abstract: An abradable coating may include a rare earth silicate. The abradable coating may be deposited over a substrate, an environmental barrier coating, or a thermal barrier coating. The abradable coating may be deposited on a gas turbine blade track or a gas turbine blade shroud to form a seal between the gas turbine blade track or gas turbine blade shroud and a gas turbine blade. The abradable coating may also include a plurality of layers, such as alternating first and second layers including, respectively, a rare earth silicate and stabilized zirconia or stabilized hafnia.

Abstract: A coating including a bond layer deposited on a substrate. The bond layer includes a rare earth silicate and a second phase, the second phase including at least one of silicon, silicides, alkali metal oxides, alkali earth metal oxides, glass ceramics, Al2O3, TiO2, Ta2O5, HfO2, ZrO2, HfSiO4, ZrSiO4, HfTiO4, ZrTiO4, or mullite. The coating may provide thermal and/or environmental protection for the substrate, especially when the substrate is a component of a high-temperature mechanical system.

Abstract: A thermal barrier coating composition including a base oxide; a primary dopant including ytterbia; a first co-dopant including samaria; and a second co-dopant including at least one of lutetia, scandia, ceria, gadolinia, neodymia, or europia.

Abstract: A coating including a CMAS-resistant layer with a rare earth oxide. The CMAS-resistant layer is essentially free of zirconia and hafnia, and may further include at least one of alumina, silica, and combinations thereof.

Abstract: An enhanced environmental barrier coating for a silicon containing substrate. The enhanced barrier coating may include a bond coat doped with at least one of an alkali metal oxide and an alkali earth metal oxide. The enhanced barrier coating may include a composite mullite bond coat including BSAS and another distinct second phase oxide applied over said surface.

Abstract: A multilayer article comprises a substrate comprising a ceramic or a silicon-containing metal alloy. The ceramic is a Si-containing ceramic or an oxide ceramic with or without silicon. An outer layer overlies the substrate and at least one intermediate layer is located between the outer layer and the substrate. An optional bond layer is disposed between the at least one intermediate layer and the substrate. The at least one intermediate layer may comprise an optional chemical barrier layer adjacent the outer layer, a mullite-containing layer and an optional chemical barrier layer adjacent to the bond layer or substrate. The outer layer comprises a compound having a low coefficient of thermal expansion selected from one of the following systems: rare earth (RE) silicates; at least one of hafnia and hafnia-containing composite oxides; zirconia-containing composite oxides and combinations thereof.

Abstract: A multilayer article includes a substrate that includes at least one of a ceramic compound and a Si-containing metal alloy. An outer layer includes stabilized zirconia. Intermediate layers are located between the outer layer and the substrate and include a mullite-containing layer and a chemical barrier layer. The mullite-containing layer includes 1) mullite or 2) mullite and an alkaline earth metal aluminosilicate. The chemical barrier layer is located between the mullite-containing layer and the outer layer. The chemical barrier layer includes at least one of mullite, hafnia, hafnium silicate and rare earth silicate (e.g., at least one of RE2SiO5 and RE2Si2O7 where RE is Sc or Yb). The multilayer article is characterized by the combination of the chemical barrier layer and by its lack of a layer consisting essentially of barium strontium aluminosilicate between the mullite-containing layer and the chemical barrier layer.

Abstract: A barrier layer for a silicon containing substrate which inhibits the formation of gaseous species of silicon when exposed to a high temperature aqueous environment comprises a barium-strontium alumino silicate.

Abstract: A barrier layer for a silicon containing substrate which inhibits the formation of gaseous species of silicon when exposed to a high temperature aqueous environment comprises a barium-strontium alumino silicate.

Abstract: A barrier layer for a silicon containing substrate which inhibits the formation of gaseous species of silicon when exposed to a high temperature aqueous environment comprises a yttrium silicate.

Abstract: A barrier layer for a silicon containing substrate which inhibits the formation of gaseous species of silicon when exposed to a high temperature aqueous environment comprises a yttrium silicate.

Abstract: A barrier layer for a silicon containing substrate which inhibits the formation of gaseous species of silicon when exposed to a high temperature aqueous environment comprises a calcium alumino silicate.

Abstract: A barrier layer for a silicon containing substrate which inhibits the formation of gaseous species of silicon when exposed to a high temperature aqueous environment comprises a calcium alumino silicate.

Abstract: High temperature alloys resistant to degradation and oxidation are provided. In accordance with preferred embodiments, alloys comprising from about 0.1 to about 50 atomic percent silicon, from about 10 to about 80 atomic percent aluminum, and at least one metal selected from the group consisting of chromium, iridium, rhenium, palladium, platinum, rhodium, ruthenium, osmium, molybdenum, tungsten, niobium and tantalum are formed. Shaped bodies and structural members comprising such alloys are also described as are methods for their fabrication.

Abstract: A silicon-base ceramic substrate is provided with a mullite chemical barrier/thermal barrier coating uniformly bonded to a surface. The coating is substantially free of amorphous mullite.

Abstract: A silicon-base ceramic substrate is provided with a mullite coating by flame-spraying heated crystalline mullite powders onto a substrate that is preheated to a temperature in excess of 800.degree. C. The mullite immediately crystallizes as it solidifies.