During a material removal method, a component is received that includes a component body and a coating on the component body. The component body includes metallic first material. The coating includes second material that is different from the first material. A solution is received that includes nitric acid and hydrogen peroxide. At least a portion of the coating is subjected to the solution in order to remove at least some of the second material from the component.

Fracture-resistant and self-lubricating wear surfaces are provided. In an implementation, a machine surface that is subject to wear is coated with or is constructed of a metallic nanostructure to resist the wear and to provide fracture-resistant hardness, built-in lubrication, and thermal conductivity for heat-sinking friction. The metallic nanostructured surface may be used, for example, on a face seal, bushing, bearing, thrust member, or hydraulic flow passage of an electric submersible pump. In an implementation, the metallic nanostructured surface is a nanocrystalline alloy including nanograin twins of a body-centered cubic (BCC), face-centered cubic (FCC), or hexagonal closest packed (HCP) metal. The nanostructured alloy may include atoms of copper, silver, gold, iron, nickel, palladium, platinum, rhodium, beryllium, magnesium, titanium, zirconium, or cobalt, and may provide more hardness and lubricity than diamond-like carbon coatings or carbides.

In one aspect, a calcium-magnesium alumino-silicate (CMAS)-resistant coating includes an outer coating having a plurality of columnar structures formed during material deposition due to preferential material accumulation and a plurality of generally vertically-oriented gaps separating adjacent columnar structures. The columnar structures include a plurality of randomly-oriented particle splats and a CMAS-reactive material and have a total porosity of less than five percent. The plurality of generally vertically-oriented gaps extend from an outermost surface of the outer coating to a first depth of the outer coating equal to or less than a total thickness of the outer coating. The vertically-oriented gaps have a median gap width of less than five micrometers.

A cast component includes a cast body that has a single crystal microstructure and an internal corner bounding an internal cavity. The single crystal microstructure defines a critical internal residual stress with respect to investment casting of the cast body using a refractory metal core beyond which the single crystal microstructure recrystallizes under a predetermined condition. The internal corner has a corner radius that is greater than a critical corner radius below which an amount of internal residual stress in the single crystal microstructure exceeds the critical internal residual stress. The internal cavity includes a cross section less than about 20 mils near the corner radius.

A gas turbine engine component includes an airfoil that has first and second structural airfoil segments that are bonded to each other in at least one diffusion joint. The first and second structural airfoil segments are formed of, respectively, first and second materials. The first and second materials are: different base-metal metallic alloys, a metallic alloy and a ceramic-based material, or ceramic-based materials that differ by at least one of composition and microstructure. The first structural airfoil segment is a first skin and the second structural airfoil segment is a hollow core that has an airfoil shape.

A weld clad layer having a substantially equiaxed grain microstructure may be formed by forming a repair area in a substrate, depositing a first layer of laser deposition spots in the repair area, and depositing a second layer of laser deposition spots over the first layer of laser deposition spots. The first layer of laser deposition spots may comprise a first laser deposition spot and a second laser deposition spot adjacent to the first laser deposition spot. The first laser deposition spot may solidify prior to deposition of the second laser deposition spot. The first layer of laser deposition spots may comprise titanium or titanium alloy.

A turbine engine component includes a wall extending from a leading edge to a trailing edge. The wall includes a hot side facing a gaspath when the gaspath component is in an installed state, and a cold side opposite the hot side. At least one minicore cooling circuit is disposed between the hot side and the cold side within the wall. At least one cooling fluid inlet connects the minicore cooling circuit to a coolant source. At least one film cooling hole connects the minicore cooling circuit to the hot side surface. The minicore cooling circuit includes an edge plenum having a thickness normal to the hot side surface that is larger than a thickness of the majority of the minicore cooling circuit normal to the hot side surface. The edge plenum is a portion of the at least one minicore cooling circuit most proximate to one of the leading edge and the trailing edge.

An integrally bladed rotor in which a hub and a web are formed from a fine grain microstructure using an investment casting process or from metal powder with a HIP process, and a plurality of rotor blades formed from a coarse grain microstructure using a metal additive manufacturing process, where the hub and the web and the rotor blades are formed as a single piece and from the same material.

A component includes a component body that is configured for use in a gas turbine engine. The component body includes first and second structural segments that are bonded to each other in at least one diffusion joint. The first and second structural segments are formed of, respectively, first and second materials. The first and second materials are different base-metal alloys, a metallic alloy and a ceramic-based material, or ceramic-based materials that differ by at least one of composition and microstructure.

A gas turbine engine assembly comprising a rotor, a gas path component, and a carrier. The rotor includes a shaft adapted to rotate about an axis and a gas-path component that extends from the shaft for rotation therewith about the axis. The carrier extends around the gas-path component to block gasses from passing over the gas-path component during rotation of the rotor.