A gas turbine engine includes a plurality of rotating components housed within a compressor section and a turbine section. A first tap is connected to the compressor section and configured to deliver air at a first pressure. A heat exchanger is connected downstream of the first tap. A flowpath is defined between a rotating surface and a non-rotating surface. The flowpath is connected downstream of the heat exchanger and is configured to deliver air to at least one of the plurality of rotating components. At least a portion of the non-rotating surface and the rotating surface includes a base metal. An insulation material is disposed on a surface along the flowpath.

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.

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 bushing for a stator vane assembly of a gas turbine engine has a tubular member that is coaxial about a longitudinal axis and that extends a length between a first axial end and a second axial end. The tubular member has an outside circumferential surface thereon and an inside circumferential surface therein and is manufactured from a cobalt based alloy, a nickel based alloy, a graphite material, a cermet material or an alloy matrix comprising titanium, aluminum, niobium, manganese, boron, and carbon and a solid lubricant being dispersed in the alloy matrix. A portion of the inside circumferential surface and/or a portion of the outside circumferential surface has a wear resistant material thereon.

A coated substrate comprising a metal or metal alloy such as a high speed steel, TiAl based alloy or Ni based alloy or an electrically conductive ceramic material, wherein the coating comprises a hard material protective coating comprising alternating layers of different compositions, wherein a first composition of the alternating layers comprises silicon, Si, and/or a second composition of the alternating layers comprises boron, B.

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 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.

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 μm and about 40 μm. 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 example ferroelastic ceramic composition includes at least one compound having a relative chemical formula of A.sub.XB.sub.YC.sub.(1-X-Y)D. Element A, element B, and element C are independently selected from different members of the group consisting of yttrium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium. Element D is selected from the group consisting of phosphate, niobate, and tungstate. X and Y are each equal to or greater than zero and less than one. X and Y are collective less than one.

Embodiments of the present disclosure generally relate to protective coatings on turbine blades, turbine disks, and other aerospace components and methods for depositing the protective coatings. In one or more embodiments, a turbine blade includes a blade portion and a root coupled to the blade portion, where the root contains a protective coating disposed thereon. The protective coating is or contains one or more deposited crystalline film containing at least one of a metal oxide, a metal nitride, or a metal oxynitride and has a thickness of about 100 nm to about 10 μm. In some examples, a turbine blade assembly includes a disk and a plurality of the turbine blades coupled to the disk. The protective coating is disposed on the root on the turbine blade and/or a receiving surface on the turbine disk.