In some examples, a method for forming an abrasive coating on a component (e.g., a turbine blade, vane, or knife ring) of a gas turbine engine. The method may include forming an abrasive coating system on a substrate, the abrasive coating system including an abrasive coating including a plurality of abrasive particles in a metal matrix; machining the abrasive coating on the substrate to define a machined abrasive coating having an abrasive coating thickness profile; and etching an outer surface of the machined abrasive coating to remove a portion of the metal matrix and form an etched metal matrix such that the abrasive particles protrude from the metal matrix.

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.

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.

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 method for forming a ceramic matrix composite (CMC) component with an internal cooling channel includes partially densifying a first fiber preform to form a portion of a final ceramic matrix volume, machining a first channel into a surface of the partially densified first fiber preform, covering the first channel with a fibrous member to form a near net shape fiber preform with an internal passage formed by the first channel and the fibrous member, and densifying the near net shape fiber preform.

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.

In some examples, a method for forming an abrasive coating on a component (e.g., a turbine blade, vane, or knife ring) of a gas turbine engine. The method may include forming an abrasive coating system on a substrate, the abrasive coating system including an abrasive coating including a plurality of abrasive particles in a metal matrix; machining the abrasive coating on the substrate to define a machined abrasive coating having an abrasive coating thickness profile; and etching an outer surface of the machined abrasive coating to remove a portion of the metal matrix and form an etched metal matrix such that the abrasive particles protrude from the metal matrix.

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.

An integrally bladed rotor, including: a plurality of blades integrally formed with a hub as a single component, each of the plurality of blades having a blade body extending from the hub to an opposed blade tip surface along a longitudinal axis, wherein the blade body defines a pressure side and a suction side, and wherein the blade body includes a cutting edge defined between the blade tip surface of the blade body and the pressure side of the blade body, wherein the cutting edge is configured to abrade a seal section of an engine case. A method for manufacturing an integrally bladed rotor includes: forming a plurality of airfoils integrally with a hub to form a single component, each of the plurality of airfoils having an opposed tip surface with respect to the hub extending along a longitudinal axis, wherein each of the plurality of airfoils defines a pressure side and a suction side; and forming a cutting edge between the tip surface and the pressure side of each of the plurality of airfoils, wherein the cutting edge is configured to abrade a seal section of an engine case.

A gas turbine component includes a substrate and a corrosion resistant layer coupled to the substrate. The corrosion resistant layer includes zirconium silicate and is configured to protect the substrate from exposure to a vanadium corrodent.