A composite article includes a substrate, at least one protective layer on the substrate, and an intermediate layer between the protective layer and the substrate. The intermediate layer includes a first material that occupies a first continuous region and a second material that occupies a second continuous region next to the first continuous region. The first continuous region and the second continuous region are each in contact with the substrate and the protective layer.

An article may include a substrate including a ceramic or a CMC; a bond layer on the substrate; and a diffusion barrier layer between the substrate and the bond layer. The diffusion barrier layer may include at least one of molybdenum metal, tantalum metal, tungsten metal, or niobium metal. In some examples, the article may include a stabilizing layer that includes at least one of a silicide of molybdenum (MoSi.sub.2), tantalum (TaSi.sub.2), tungsten (WSi.sub.2), or niobium (NbSi.sub.2), between the diffusion barrier layer and the bond layer.

In some examples, a braze material includes a first set of particles, a second set of particles, and a polymeric binder. The first set of particles includes a braze powder, where the braze powder comprises an Si-containing alloy. The first set of particles defines an average or median particle diameter between about 1 m and about 40 m. The second set of particles includes at least one of SiC or a transition metal carbide, where the second set of particles has a multimodal particle size distribution.

An article includes a substrate, a bond coat on the substrate, and a multilayer environmental barrier coating (EBC) on the bond coat. The multilayer EBC includes a first EBC layer defining a first thickness and a second EBC layer defining a second thickness. The first EBC layer includes a first rare earth disilicate and a first concentration of a sintering aid that includes alumina. The second EBC layer includes a second rare earth disilicate and a second concentration of the sintering aid that includes alumina, less than the first concentration of the sintering aid.

An article includes a ceramic-based substrate and a barrier layer on the ceramic-based substrate. The barrier layer includes a matrix, diffusive particles, and gettering particles. The gettering particles include at least one of non-gas-evolving particles and porous particles. An article and a method are also disclosed.

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 repaired oxidation and corrosion resistant coating may comprise a repair material applied to a damaged portion of the oxidation and corrosion resistant coating. The repair material may be free of hexavalent chromium and may be compatible with a plurality of oxidation and corrosion resistant materials that comprise hexavalent chromium. The repair material may be burnished. The oxidation and corrosion resistant coating may comprise hexavalent chromium.

A blade includes a blade body extending from a blade root to an opposed blade tip surface along a longitudinal axis. The blade body defines a pressure side and a suction side. The blade body includes a cutting edge defined where the tip surface of the blade body meets the pressure side of the blade body. The cutting edge is configured to abrade a seal section of an engine case. A method for manufacturing a blade includes forming an airfoil with a root and an opposed tip surface along a longitudinal axis, wherein the airfoil defines a pressure side and a suction side. The method also includes forming a cutting edge where the tip surface of the airfoil meets the pressure side of the airfoil.

A turbomachine component is provided having at least two sub-components that are separated by a parting joint and each have a sealing surface at the parting joint, at least one of the two sealing surfaces being convex in order to form a linear contact of the two sealing surfaces. At least one of the sealing surfaces has a coating on it which includes a hard material, is a maximum of 30 m thick and is applied using a vapour deposition method, or a coating which includes a chrome-containing alloy, is a maximum of 30 m thick and is applied by a vapour deposition method, or is a maximum of 300 m thick and applied using a thermal spraying method.

A blade includes a blade body extending from a blade root to an opposed blade tip surface along a longitudinal axis. The blade body defines a pressure side and a suction side. The blade body includes a cutting edge defined where the tip surface of the blade body meets the pressure side of the blade body. The cutting edge is configured to abrade a seal section of an engine case. A method for manufacturing a blade includes forming an airfoil with a root and an opposed tip surface along a longitudinal axis, wherein the airfoil defines a pressure side and a suction side. The method also includes forming a cutting edge where the tip surface of the airfoil meets the pressure side of the airfoil.