Abstract:
A gas turbine engine includes an airfoil having a core that has a first hardness and a surface on the core. The surface includes a plurality of geometric features that have a second, greater hardness. The geometric features define a surface porosity by area percent and a corresponding surface solidity by area percent. The surface includes a ratio of the surface solidity divided by the surface porosity that is 1.8 or greater. The geometric features and the ratio establish the surface to be hydrophobic, and the second, greater hardness and the ratio establish an erosion rate of the surface that is equal to or less than an erosion rate of the core under identical erosion conditions.
Abstract:
A method for processing a powder material includes cleaning surfaces of a powder material that has spherical metal particles, coating the cleaned surfaces with an organic bonding agent, mixing the coated particles with a dispersion that contains ceramic nanoparticles, drying the mixture to remove a carrier of the dispersion and deposit the ceramic nanoparticles with a spaced-apart distribution onto the organic bonding agent on the surfaces of the particles, and thermally removing the organic bonding agent to attach the ceramic nanoparticles to the surface of the particles.
Abstract:
A method of producing a ceramic material includes heating solid silicon monoxide to provide gaseous silicon monoxide, and exposing a structure having a free-carbon-containing material to the gaseous silicon monoxide to convert free carbon of the free-carbon-containing material to silicon carbide. Also disclosed is an intermediate article that includes a solid structure having free carbon and a solid, in-situ source of silicon monoxide gas. Also disclosed is a composition that includes a polymeric carrier phase and particulate of solid silicon monoxide dispersed in the polymeric carrier phase.
Abstract:
A method for making a plurality of metallic nanowires includes combining a metallic precursor with a solvent to form a metallic precursor solution. A quantity of oxalic acid is added to the metallic precursor solution to form a reduction solution. A plurality of nanowires are precipitated out from the reduction solution.
Abstract:
A feedstock for an additive manufacturing process includes a pre-ceramic polymer intermixed with a base material. A method of additive manufacturing includes melting and pyrolizing a feedstock containing metal and a pre-ceramic polymer. An article of manufacture includes an additive manufacturing component including a pyrolized feedstock.
Abstract:
A gas turbine engine article includes a substrate and an environmental barrier coating (EBC) system disposed on the substrate. The EBC system includes, from the substrate, a dense bond coat layer, a porous bond coat layer, and a topcoat layer in contact with the porous bond coat layer at an interface. The porous bond coat layer includes a matrix, oxygen-scavenging gas-evolution particles dispersed through the matrix, and engineered buffer pores. The oxygen-scavenging gas-evolution particles react with oxygen and generate a gaseous byproduct that diffuses through the interface to escape the EBC system. The engineered buffer pores buffer diffusion of gaseous byproduct to the interface by retaining at least a portion of the gaseous byproduct.
Abstract:
An article includes a ceramic-based substrate and a barrier layer on the ceramic-based substrate. The barrier layer includes a matrix phase and gettering particles in the matrix phase. The gettering particles with an aspect ratio greater than one are aligned such that a maximum dimension of the gettering particles extends along an axis that is generally parallel to the substrate. The barrier layer includes a dispersion of diffusive particles in the matrix phase. A composite material and a method of applying a barrier layer to a substrate are also disclosed.
Abstract:
A gas turbine engine article includes a substrate and an environmental barrier coating (EBC) system disposed on the substrate. The EBC system includes, from the substrate, a dense bond coat layer, a porous bond coat layer, and a topcoat layer in contact with the porous bond coat layer at an interface. The porous bond coat layer includes a matrix, oxygen-scavenging gas-evolution particles dispersed through the matrix, and engineered buffer pores. The oxygen-scavenging gas-evolution particles react with oxygen and generate a gaseous byproduct that diffuses through the interface to escape the EBC system. The engineered buffer pores buffer diffusion of gaseous byproduct to the interface by retaining at least a portion of the gaseous byproduct.
Abstract:
A powder material includes spherical metal particles and a spaced-apart distribution of ceramic nanoparticles attached to the surfaces of the particles.
Abstract:
A coated article including an article having a surface; an oxidation resistant bond coat layer deposited on the surface, the oxidation resistant bond coat layer comprising a healing silica matrix and at least one oxygen scavenger forming a metal silicide network dispersed within the healing silica matrix; and a top coat layer disposed upon the oxidation resistant bond coat layer, whereby the oxidation resistant bond coat layer is operable to seal a crack in the top coat layer.