摘要:
A coating system on a superalloy or silicon-containing substrate of an article exposed to high temperatures. The coating system includes a coating layer that overlies the substrate and is susceptible to hot corrosion promoted by molten salt impurities. A corrosion barrier coating overlies the coating layer and contains at least one rare-earth oxide-containing compound that reacts with the molten salt impurities to form a dense, protective byproduct barrier layer.
摘要:
A coating and method for overcoating a TBC on a component used in a high-temperature environment, such as the combustor section of an industrial gas turbine. The coating defines the outermost surface of the component and is formed of at least two layers having different compositions. An inner layer of the coating contains alumina in a first silica-containing matrix material that is free of zinc titanate. An outer layer of the coating contains alumina, a glass material, and zinc titanate in a second silica-containing matrix material. The outer layer of the coating has a surface roughness of not greater than three micrometers Ra and forms the outermost surface of the component. The coating reduces the component temperature by reducing the convective and radiant heat transfer thereto.
摘要:
An introduction system for introducing an atmosphere into an interior of an autoclave alters an existing atmosphere. The introduction system comprises at least one source of actuating gas; an actuating mechanism, a pressure barrier that separates an interior of the autoclave from ambient exterior atmosphere; and a containment vessel that is located at least partially in the interior of the autoclave. The containment vessel comprises a plurality of walls, at least one of the walls comprising a release wall structure of the containment vessel, a vapor producing material cavity, where the walls define the vapor producing material cavity; and an opening element. The opening element is movable by the opening actuator device. The release wall structure of the containment vessel is rapidly opened by the opening element to effect a rapid release of vapor producing material in the vapor producing material cavity into the interior of the autoclave. The autoclave is provided with at least an increased pressure, so a rapid release of vapor producing material in the vapor producing material cavity into the interior of the autoclave causes the vapor producing material to vaporize into a vapor, thus altering an atmosphere in the autoclave. The actuating mechanism comprises an opening actuator device. The at least one source of actuating gas in communication with the opening actuator device and flow from the at least one source of actuating gas is controlled by a control device.
摘要:
A method for metallurgically bonding a stator bar to a coupling to reduce the incidence of leak paths resulting from corrosion. The stator bar comprises strands through which a liquid coolant can flow. Adjacent ends of the strands are received in an interior cavity of the coupling through an opening in the coupling. A joining material is provided on a first portion of the stator bar within the coupling opening and adjacent the ends of the strands. The first portion is heated to melt the joining material. At essentially the same time, a second portion of the stator bar outside the coupling is also heated. Once the joining material is suitably molten, the first portion is allowed to cool while the second portion remains heated, thereby causing the joining material nearest the ends of the strands to solidify first.
摘要:
A method of fabricating a component for a gas turbine engine is provided. The method includes applying a bond coat to at least a portion of the component, applying a dense vertically cracked (DVC) thermal barrier coating to at least a portion of the bond coat using a spray mechanism positioned a first distance from the component, and overlying at least a portion of the DVC thermal barrier coating with a soft coat thermal barrier coating using a spray mechanism that is positioned a second distance away from the component, wherein the second distance is greater than the first distance to facilitate adherence of the soft coating thermal barrier coating to the DVC thermal barrier coating.
摘要:
A coated article comprises a substrate; and a multilayer thermal barrier coating disposed on the substrate, the multilayer thermal barrier coating comprising at least a first layer comprising a first ceramic composition having a thermal conductivity less than 1 W/m° K; a second layer having an erosion resistance greater than or equal to dense vertically cracked 8% yttrium stabilized zirconia, wherein percent is based on a total weight of yttrium and zirconia, and a third layer comprising the first ceramic composition or the second composition, wherein the first, second, and third layers are arranged such that the first ceramic composition and the second composition are in alternating layers.
摘要:
A coating system on a superalloy or silicon-containing substrate of an article exposed to high temperatures. The coating system includes a coating layer that overlies the substrate and is susceptible to hot corrosion promoted by molten salt impurities. A corrosion barrier coating overlies the coating layer and contains at least one rare-earth oxide-containing compound that reacts with the molten salt impurities to form a dense, protective byproduct barrier layer.
摘要:
A method for metallurgically bonding a stator bar to a coupling to reduce the incidence of leak paths resulting from corrosion. The stator bar comprises strands through which a liquid coolant can flow. Adjacent ends of the strands are received in an interior cavity of the coupling through an opening in the coupling. A joining material is provided on a first portion of the stator bar within the coupling opening and adjacent the ends of the strands. The first portion is heated to melt the joining material. At essentially the same time, a second portion of the stator bar outside the coupling is also heated. Once the joining material is suitably molten, the first portion is allowed to cool while the second portion remains heated, thereby causing the joining material nearest the ends of the strands to solidify first.
摘要:
The present invention provides a method of removing copper oxide deposits from stator water cooling system piping material surfaces. The present invention disconnects the generator from the stator water cooling system, connects bridging piping to the stator water cooling system at the points from which the generator was disconnected to allow the stator water cooling system to operate without the generator, provides a sufficient amount of an aqueous solution of an agent which dissolves or removes copper oxide deposits from piping material surfaces for a time sufficient to dissolve or remove substantially all copper oxide deposits, and rinses the piping material surfaces with sufficient water until the output water from the rinsing of the piping material surfaces is essentially neutral.
摘要:
A double wall hot gas path part for turbines, such as an airfoil, combustor, duct or shroud, comprises an outer skin and an inner support wall that are metallurgically bonded to one another. The double wall contains integral channels for passage of cooling air adjacent to the skin. The skin may be a metal alloy skin or a microlaminate structure, including microlaminate composite structures. Microlaminate composites typically have a lower density than that of the material used for the support wall, and a simplified internal geometry, which promote weight reductions in the parts and increases in engine operating efficiency.