Abstract:
A method for preparing an alloy nanocellular foam includes at least partially coating a nanocellular precursor into a multiple composition nanoparticle precursor and converting the multiple composition nanoparticle precursor into an alloy via a diffusion process.
Abstract:
An additive manufacturing system includes an energy gun having a plurality of energy source devices each emitting an energy beam. A primary beam melts a selected region of a substrate into a melt pool and at least one secondary beam heat-conditions the substrate proximate the melt pool to reduce workpiece internal stress and/or enhance micro-structure composition of the workpiece.
Abstract:
A solid-state method for forming an alloy includes providing a powder that has heterogeneous particles with a ratio, by weight, of an amount of nickel to an amount of a metal. The ratio is selected in accordance with a compositional ratio that can substantially bear a nickel intermetallic precipitate of the nickel and the metal. The heterogeneous particles are then consolidated and thermally treated to interdiffuse the nickel and the metal. The interdiffused nickel and metal are then precipitation treated to precipitate the nickel intermetallic.
Abstract:
A nanocellular foam has pores, interconnecting ligaments, and nodes where three or more ligaments intersect. The ligament cross section thickness is less than 200 microns and the distance between nodes is less than 1000 microns. A method of fabricating a nanocellular foam comprising forming a compact with one or more powders and applying energy to cause at least one or more powders to undergo a change in state is disclosed.
Abstract:
A high temperature nanocellular foam seal material has pores, interconnecting ligaments, and nodes where three or more ligaments intersect. The ligament cross-section thickness is less than 200 microns and the distance between nodes is less than 1000 microns. The material's high compliance and elastic springback can be tailored to an application by varying the foam architecture. Metal, intermetallic, and ceramic nanocellular foams can be used as seal materials in the hot gas path of a turbine engine.
Abstract:
An erosion resistant and hydrophobic article includes 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 coating a ceramic matrix composite substrate (12) with an environmental barrier coating (18) includes the steps of: treating a surface (20) of a ceramic matrix composite substrate (12) to adjust wettability of the surface (20); and applying an aqueous slurry-based environmental barrier coating (18) to the surface (20). The treating step can be a plasma treatment to remove organic contaminants, and can also be a treatment to modify oxidative state of the surface (20). The treatment can produce a surface (20) for treatment that is hydrophilic and has a contact angle with aqueous-slurry coating materials of less than 40 degrees.
Abstract:
A method and system 10 for coating metallic powder particles 12 is provided. The method includes: disposing an amount of metallic powder particulates 12 within a fluidizing reactor 14; removing moisture adhered to the powder particles 12 disposed within the reactor 14 using a working gas; coating the powder particles 12 disposed within the reactor 14 using a precursor gas; and purging the precursor gas from the reactor 14 using the working gas.
Abstract:
A process for densification of a ceramic matrix composite comprises forming a reinforcing ceramic continuous fiber stack (10) having a central zone (36) bounded by an outer zone (30) adjacent; locating first particles within the central zone (36); coating the first particles and the ceramic fibers with silicon carbide through chemical vapor infiltration; locating second particles within the outer zone (30); coating the second particles and the ceramic fibers with silicon carbide through chemical vapor infiltration; forming the stack (10) into a predetermined three dimensional shape; and densifying the stack (10) .