摘要:
A process and apparatus for forming wires, such as wires used as feedstock in welding, brazing, and coating deposition processes. The process and apparatus generally entail feeding through a passage a quantity of powder particles of a size and composition that render the particles susceptible to microwave radiation. As the particles travel through the passage, the particles within the passage are subjected to microwave radiation so that the particles couple with the microwave radiation and are sufficiently heated to melt at least a radially outermost quantity of particles within the passage. The particles are then cooled so that the radially outermost quantity of particles solidifies to yield a wire having a consolidated outermost region surrounding an interior region of the wire.
摘要:
A process and apparatus for forming wires, such as wires used as feedstock in welding, brazing, and coating deposition processes. The process and apparatus generally entail feeding through a passage a quantity of powder particles of a size and composition that render the particles susceptible to microwave radiation. As the particles travel through the passage, the particles within the passage are subjected to microwave radiation so that the particles couple with the microwave radiation and are sufficiently heated to melt at least a radially outermost quantity of particles within the passage. The particles are then cooled so that the radially outermost quantity of particles solidifies to yield a wire having a consolidated outermost region surrounding an interior region of the wire.
摘要:
A process for heating powder materials by microwave radiation so that heating and sintering or melting progressively and directionally occurs within the powder materials. The process generally entails forming a structure from a powder by arranging the powder in a mass according to size of particles of the powder so that the particles are progressively arranged within at least a region of the mass from smallest to largest. The mass is then subjected to microwave radiation so that the particles within the mass progressively couple with the microwave radiation according to size, the smallest particles coupling first and heating faster than larger particles of the powder, and the largest particles coupling last and heating slower than smaller particles of the powder. As a result of the progressive arrangement of the particles, the mass is progressively and directionally heated by the microwave radiation.
摘要:
A process for heating powder materials by microwave radiation so that heating and sintering or melting progressively and directionally occurs within the powder materials. The process generally entails forming a structure from a powder by arranging the powder in a mass according to size of particles of the powder so that the particles are progressively arranged within at least a region of the mass from smallest to largest. The mass is then subjected to microwave radiation so that the particles within the mass progressively couple with the microwave radiation according to size, the smallest particles coupling first and heating faster than larger particles of the powder, and the largest particles coupling last and heating slower than smaller particles of the powder. As a result of the progressive arrangement of the particles, the mass is progressively and directionally heated by the microwave radiation.
摘要:
A process for forming a coating on a surface of a substrate, so that heating of the coating material is selective and sufficient to cause at least partial melting of the coating material and permit bonding to the substrate without excessively heating the substrate so as not to significantly degrade its properties. The process generally entails forming a brazing paste containing powder particles dispersed in a binder. The particles are formed of a composition that is susceptible to microwave radiation. The brazing paste is then applied to the surface of the substrate and subjected to microwave radiation so that the particles couple with the microwave radiation and are sufficiently heated to burn off the binder and then at least partially melt to form an at least partially molten layer on the substrate. The microwave radiation is then interrupted to allow the at least partially molten layer to cool, solidify, and form the coating.
摘要:
A process for forming a coating on a surface of a substrate, so that heating of the coating material is selective and sufficient to cause at least partial melting of the coating material and permit bonding to the substrate without excessively heating the substrate so as not to significantly degrade its properties. The process generally entails forming a brazing paste containing powder particles dispersed in a binder. The particles are formed of a composition that is susceptible to microwave radiation. The brazing paste is then applied to the surface of the substrate and subjected to microwave radiation so that the particles couple with the microwave radiation and are sufficiently heated to burn off the binder and then at least partially melt to form an at least partially molten layer on the substrate. The microwave radiation is then interrupted to allow the at least partially molten layer to cool, solidify, and form the coating.
摘要:
A process and apparatus for brazing a metal alloy component, such as a superalloy component of a gas turbine engine. The process employs a plasma torch in a non-transferred arc mode to generate an electric arc between an electrode and a housing in which an orifice is defined. A plasma gas is flowed through the arc so as to ionize the plasma gas, and the resulting ionized plasma gas is discharged through the orifice to form a plasma jet. The plasma torch is configured so that the plasma jet is shrouded from a surrounding oxidizing atmosphere by a shielding gas flowing cocurrently with the plasma jet. A braze alloy material is introduced into the plasma jet, which is directed at a surface of the component to form a brazement that is metallurgically bonded to the component without melting the component.
摘要:
A shell mold for casting molten material to form an article is described. The mold includes a shell for containing the molten material, formed from at least one of yttrium silicates, zirconium silicates, hafnium silicates, and rare earth silicates. The mold also includes a facecoat disposed on an inner surface of the shell that contacts the molten material. The facecoat can be made from the materials described above. A method of casting a niobium-silicide article is also described, using the shell mold described herein. A method of making the ceramic shell mold is described as well, along with a slurry composition used in the manufacture of the shell mold.
摘要:
A system and method for refurbishing forged components. The system includes an identification subsystem for identifying a forged component for refurbishment, a removal subsystem for removing portions of the forged component, and a rebuilding subsystem for rebuilding the forged component, the rebuilding subsystem including an assembly for adding a non-molten material to the forged component.
摘要:
A gamma prime nickel-base superalloy and components formed therefrom that exhibit improved high-temperature dwell capabilities, including creep and hold time fatigue crack growth behavior. A particular example of a component is a powder metallurgy turbine disk of a gas turbine engine. The gamma-prime nickel-base superalloy contains, by weight, 16.0 to 30.0% cobalt, 11.5 to 15.0% chromium, 4.0 to 6.0% tantalum, 2.0 to 4.0% aluminum, 1.5 to 6.0% titanium, up to 5.0% tungsten, 1.0 to 7.0% molybdenum, up to 3.5% niobium, up to 1.0% hafnium, 0.02 to 0.20% carbon, 0.01 to 0.05% boron, 0.02 to 0.10% zirconium, the balance essentially nickel and impurities, wherein the titanium:aluminum weight ratio is 0.5 to 2.0.