Abstract:
A method of providing turbulation on the inner surface of a passage hole (e.g., a turbine cooling hole) is described. The turbulation is first applied to a substrate which can eventually be inserted into the passage hole. The substrate is often a bar or tube, formed of a sacrificial material. After the turbulation is applied to the substrate, the substrate is inserted into the passage hole. The turbulation material is then fused to the inner surface, using a conventional heating technique. The sacrificial substrate can then be removed from the hole by various techniques. Related articles are also described.
Abstract:
The present invention provides a method of repairing a turbine nozzle segment having one or more vanes disposed between outer and inner bands. The method includes separating at least one of the outer and inner bands from the vanes. The vanes are cut through in close proximity to the band being replaced. A newly manufactured replacement band including protruding vane stubs is provided for each one of the original bands being replaced. The replacement band is attached to the vanes by welding.
Abstract:
An electrode for rejuvenating a cooling passage within an airfoil, the electrode including a tip, an end, a conductive core extending between the tip and the end, and an insulating coating disposed on the conductive core. The insulating coating exposes a number of conductive strips of the conductive core extending between the tip and the end. The insulating coating forms a number of insulating portions and further exposes a number of spacer portions of the conductive core longitudinally positioned between the insulating portions. The insulating portions substantially span a distance between the tip and the end and are positioned between the conductive strips.
Abstract:
A method for forming a channel within a coated, metal-based substrate is described. In one technique, a channel-forming material is first deposited on the substrate, followed by the deposition of a bonding agent, such as a braze. One or more coatings can then be applied over the substrate. In one embodiment, the channel is formed when the channel-forming material is subsequently removed. In another embodiment, the channel is formed due to the lack of adhesion between particular channel-forming materials and the overlying bonding agent. Related articles are also described, e.g., gas turbine components which include protective coatings and a pattern of cooling channels.