Advanced environmental barrier coating bond coat systems with higher temperature capabilities and environmental resistance are disclosed. These bond coat systems can be applied to ceramic substrates such as SiC/SiC ceramic matrix composite substrates, and can provide protection from extreme temperature, mechanical loading and environmental conditions, such as in high temperature gas turbines. Example bond coat systems can include either an advanced silicon/silicide component, an oxide/silicate component, or a combination thereof.

Methods for forming sintered-bonded high temperature coatings over ceramic turbomachine components are provided, as are ceramic turbomachine components having such high temperature coatings formed thereover. In one embodiment, the method includes the step or process of removing a surface oxide layer from the ceramic component body of a turbomachine component to expose a treated surface of the ceramic component body. A first layer of coating precursor material, which has a solids content composed predominately of at least one rare earth silicate by weight percentage, is applied to the treated surface. The first layer of the coating precursor material is then heat treated to sinter the solids content and form a first sintered coating layer bonded to the treated surface. The steps of applying and sintering the coating precursor may be repeated, as desired, to build a sintered coating body to a desired thickness over the ceramic component body.

A ceramic matrix composite article includes a chemical vapor infiltration ceramic matrix composite base portion including ceramic fiber reinforcement material in a ceramic matrix material having between 0% and 5% free silicon. The ceramic matrix composite article further includes a melt infiltration ceramic matrix composite covering portion including a ceramic fiber reinforcement material in a ceramic matrix material having a greater percentage of free silicon than the chemical vapor infiltration ceramic matrix composite base portion.

Methods are provided for forming high temperature coating over ceramic components, such as ceramic turbomachine components. In various embodiments, the method includes the step or process of at least partially filling a reactor vessel with a reaction solution containing a solution-borne rare earth cation source. A silicon-containing surface region of a ceramic component is submerged in the reaction solution, and a solvothermal growth process is carried-out. During the solvothermal growth process, the reaction solution is subject to elevated temperature and pressure conditions within the reactor vessel in the presence of a silicate anion source, which reacts with the solution-borne rare earth cation source to grow a rare earth silicate layer over the silicon-containing surface region of the ceramic component.

A method for producing a coating system includes depositing a first slurry on a composite substrate, the first slurry including a first carrier fluid and boron-containing powder, removing the first carrier fluid and consolidating the boron-containing powder to form a boron-containing layer on the composite substrate, depositing a silicon-containing coating on the boron-containing layer and consolidating the silicon-containing coating to form a silicon-containing layer, and depositing at least one layer of phosphate on the silicon-containing layer.

An intermetallic matrix composite has an intermetallic matrix and a ceramic reinforcement. The intermetallic matrix comprises, in atomic percent: 28.02.0 Nb; 27.02.0 Mo; 27.02.0 Cr; 9.0 2.0 Si; 9.0 2.0 Al; and no more than 10.0 other alloying elements and impurities, if any.

A preceramic resin formulation comprising a polycarbosilane preceramic polymer and an organically modified silicon dioxide preceramic polymer. A ceramic material comprising a reaction product of the polycarbosilane preceramic polymer and organically modified silicon dioxide preceramic polymer is also described. Articles comprising the ceramic material are also described, as are methods of forming the preceramic resin formulation and the ceramic material.

A turbine ring sector made of ceramic matrix composite material has a portion forming an annular base with an inner face for defining the inner face of a turbine ring when the ring sector is mounted on a ring support structure and an outer face from which there extends an attachment portion for attaching the ring sector to the ring support structure, the ring sector further including inter-sector faces, each for facing a neighboring ring sector when the ring sector is mounted on the ring support structure; wherein the inter-sector faces are coated in an environmental barrier that is doped with an electrically-conductive compound and that presents at least one slot.

A ceramic matrix composite component for use in a gas turbine engine and method for making the same are described herein. The component includes a body and an outer region. The body includes a silicon containing ceramic composite. The outer region is on an outer surface of the body.

A method of processing a CMC component includes applying a surface formulation comprising a resin and/or a preceramic polymer to a fiber preform. The surface formulation is cured to form a surface coating, which is then pyrolyzed to convert the resin to carbon and/or the preceramic polymer to silicon carbide. After pyrolysis, the fiber preform is infiltrated with a melt comprising silicon to form a CMC component. During melt infiltration, the carbon reacts with the silicon to form silicon carbide, and the silicon carbide prevents unreacted silicon from accessing a surface region of the CMC component. Thus, after melt infiltration, a concentration of free silicon in the surface region is a low amount of about 5 vol. % or less. Upon assembling the CMC component with a metal component, diffusion between the components is inhibited or prevented by the low amount of free silicon in the surface region.