Abstract: A process for growing a substrate (24) as a melt pool (28) solidifies beneath a molten slag layer (30). An energy beam (36) is used to melt a powder (32) or a hollow feed wire (42) with a powdered alloy core (44) under the slag layer. The slag layer is at least partially transparent (37) to the energy beam, and it may be partially optically absorbent or translucent to the energy beam to absorb enough energy to remain molten. As with a conventional ESW process, the slag layer insulates the molten material and shields it from reaction with air. A composition of the powder may be changed across a solidification axis (A) of the resulting component (60) to provide a functionally graded directionally solidified product.

Abstract: Superalloy components for turbine engines are additively welded by propelling a stream of powdered filler, which includes superalloy powder filler, through a nozzle at a powder stream mass flow rate, with pressurized gas. The powdered filler stream is melted and agglomerated into a continuous melt stream with a laser or arc heating source located downstream of the nozzle. The melt stream is levitated within a magnetic field generated by at least one electromagnet coil that is oriented downstream of the heating source, and directed onto the superalloy component, by relative motion between the melt stream and the superalloy component.

Abstract: A method of selective laser brazing is provided. The method includes providing a powder including a plurality of parent core particles and a plurality of braze particles, setting a temperature of an energy source, applying the energy source to the powder, and allowing the heated powder to solidify. The plurality of parent core particles are fused together by the plurality of braze material into a desired component.

Abstract: A screen (24A-H) of a specified thickness (T) for insertion in a gap (32) between surfaces of workpieces (32, 34) to be joined by brazing. The screen thickness determines and maintains the gap thickness during brazing. The screen has a higher melting point than the braze filler material (22), is wettable by a melt of the braze filler material, and may have a higher tensile strength than the braze filler material at operating temperatures of the braze joint. The screen may include electrical resistance heating wires (52, 62) to melt the filler material (46). The screen may be covered by the filler material, forming a brazing foil (20B). The screen may include electrically conductive insulated wires (92, 93) connected to a sensor (95) such as a thermocouple or strain gauge to monitor a condition of the braze joint during subsequent operation.

Abstract: A method for forming an impact weld used in an additive manufacturing process. The method includes providing a wire having a powder filler metal core located within a sheath. The wire is then inserted within a conduit having an opening. Further, the method includes providing at least one energy pulse that interacts with the sheath to pinch off at least one segment of the wire, wherein the energy pulse causes propulsion of the segment toward a substrate with sufficient velocity to form an impact weld for welding the metal core to the substrate. In particular, the energy pulse is an electromagnetic pulse, a laser energy pulse or a high electric current pulse.

Abstract: Superalloy material components for turbine engines, including steam and combustion turbine engines are fabricated by superplastic formation of a laser-sintered preform. Superalloy material powder is sintered into a preform, such as by laser sintering. The preform is inserted within a pressurized forming furnace, containing a mold with a mold cavity defined by a mold cavity surface. The preform is heated in the forming furnace, and differential pressure is applied across the preform to deform it superplastically into abutting contact with the mold cavity surface, without fracturing the preform. Thereafter, the superalloy component is extracted from the forming furnace.

Abstract: A method of impact welding a flyer to a hollow component is provided. The method includes providing the component made of a first material and including a cavity where a weld site is disposed on a first side of the component. An incompressible material is packed against a second side of the component opposite the first side facing the cavity. A flyer made of a second material is positioned onto the weld site. The flyer is then impact welded to the component. The incompressible material prevents the deformation of the component during the impact welding. A method of impact welding a cover plate to a component is provided as well as a support system for welding repair of hollow components.

Abstract: A coating arrangement (16), including: a layer (18) of bond coat material (20); and a light-transmissive thermal barrier coating (TBC) mesh (28) having a TBC material (24) and secured in position relative to the layer of bond coat material. The coating arrangement may be positioned over a superalloy substrate material (12) and melted with a laser beam (62) to metallurgically bond the thermal barrier coating onto the substrate.

Abstract: A method including: flowing a liquid carrier medium (12) having a supply (14) of metal particles (16) across a surface (20) of a substrate (10); directing an energy beam (30) through the flowing liquid carrier medium toward the surface; and heating at least some of the metal particles in the liquid carrier medium with the energy beam to form a metallic deposit (32) that is bonded to the substrate surface and that is covered by the liquid carrier medium.

Abstract: A method including: submerging a ceramic preform (10) in a layer (12) of powdered superalloy material (14), wherein the preform defines a desired shape of a channel (60, 62, 64, 78) to be formed in a layer (42) of superalloy material; melting the powdered superalloy material around the preform without melting the preform; and cooling and re-solidifying the superalloy material around the preform to form the layer of superalloy material with the preform defining the shape of the channel therein.

Abstract: A method including spanning a relatively larger opening (50) with a support structure (72) to divide the larger opening into a plurality of relatively smaller openings (78); placing superalloy powder across the smaller openings and in contact with the support structure; and melting the superalloy powder to form a cladding layer (104) that spans the opening and is metallurgically bonded to the support structure.

Abstract: Melting energy exemplified by an arc (24) is delivered to a metal alloy material (22, 23), forming a melt pool (26). A metal oxide material (34) is delivered (33) to the melt pool and dispersed therein. The melting energy and oxide deliveries are controlled (44) to melt the alloy material, but not to melt at least most of the metal oxide material. The deliveries may be controlled so that the melting energy does not intercept the metal oxide delivery. The melting energy may be controlled to create a temperature of the melt pool that does not reach the melting point of the metal oxide. Deliveries of the melting energy and the oxide may alternate so they do not overlap in time. A cold metal transfer apparatus (22) and process (18, 19, 20) may be used for example in combination with an oxide particle pulse delivery device (42, 46).

Abstract: A method of additive manufacturing, including: placing a layer (10) of strip-cast superalloy sheet material over a subcomponent (12) leaving a gap (20) between the layer and the subcomponent; and creating a weldment (14) to the layer. Shrinkage in the layer caused by the weldment is accommodated by a decrease in the gap with reduced shrinkage stress in the weldment. The layer may be formed of more than one piece (16), and the weldment may join the pieces together with or without joining the layer to the subcomponent. The gap may again grow due to differential thermal expansion when the resulting component is placed into service, thereby functioning as a passively regulated cooling channel.

Abstract: A laser waveguide (22) with a tubular wall (24) that conducts laser energy (30) from a near end (23) to a far end (27) of the waveguide. A filler feed wire (36) slides through the hollow center of the waveguide. A laser emitter (40) delivers laser beam energy (30) to a first end of the waveguide within an acceptance angle A. The laser beam may be non-parallel to an axis (25) of the waveguide by at least 20 degrees to provide room for the laser emitter beside the feed wire. The near end of the waveguide may be flared (23C) to accept a laser beam at a greater angle from the axis. The beam exits the waveguide (32) with an annular energy distribution about the feed wire, and may be focused toward the feed wire by a lens (34) having an axial hole (37) for the wire.

Abstract: A method of removing a ceramic thermal barrier coating system (18). Laser energy (20) is applied to the thermal barrier coating system in the presence of a flux material (22) in order to form a melt (26). Upon removal of the energy, the melt solidifies to from a layer of slag (28) which is more loosely adhered to the underlying metallic substrate (12) than the original thermal barrier coating system. The slag is then broken and released from the substrate with a mechanical process such as grit blasting (30). Sufficient energy may be applied to melt an entire depth of the coating system along with a thin layer (34) of the substrate, thereby forming a refreshed surface (36) on the substrate upon resolidification.

Abstract: Methods are disclosed for cleaning a near surface region of an alloy substrate (10) in the presence of a flux material (12). A flux material is melted on the surface of the alloy substrate to a temperature sufficient to permit a reaction of the flux material with at least one tramp element present within the alloy substrate. The alloy substrate may remain solid, but diffusion of the tramp element is facilitated by an elevated temperature of the substrate. Fluxes disclosed may include a metal oxalate and/or other compounds capable of forming tramp element containing compounds by reaction with the alloy substrate to be cleaned, wherein the compounds formed have a ?Hf lower than ?100 kcal/g-mol at 25° C.

Abstract: A flux material that provides a heat outflow control layer of slag (30) on a melt pool (20) that suppresses lateral heat outflow (27) and facilitates uniaxial heat outflow (26A-D) from the melt pool at a rate that causes unidirectional crystallization in the melt pool to match a crystal direction (24) of a substrate (22). The slag may be insulative, and may flow to form a greater slag thickness (T2, T3) at the sides of the melt pool than at the middle (T1). The flux may contain constituents that warm the sides of the melt pool by exothermic reaction. The flux may be used in combination with insulating elements (32A-B, 38A-B, 44) placed on the substrate surface beside the melt pool and/or with supplemental heating of the sides of the weld.

Abstract: A gas turbine engine component (50, 100, 150, 160, 174, 206, 236), including: a surface (54) subject to loss caused by a wear instrument during operation of the component in a gas turbine engine and a performance feature (80, 82, 102, 152, 162, 172, 200, 230) associated with the surface. The surface and the performance feature interact in a manner that changes with the loss such that a change in performance of the gas turbine engine resulting from the loss is mitigated.

Abstract: A method and resulting gas turbine engine component (40) having a protective layer of metallic glass (14) deposited over a superalloy substrate (12). A further layer of ceramic insulating material (42) may be deposited over the metallic glass. The metallic glass functions as a bond coat to provide thermal insulation and mechanical compliance. The metallic glass may be deposited onto the substrate by a flux mediated laser deposition process wherein powdered alloy material (18) is melted together with powdered flux material (20). The flux material can facilitate the glass forming process by adding to the solidification confusion effect and/or by providing an active cooling effect.

Abstract: A flux (55) for superalloy laser welding and additive processing (20, 50), including constituents which decompose when heated in a laser induced plasma or to a melt temperature of the superalloy (42), creating one or more gases (46) that blanket the melt to protect it from air, while producing not more than 5 wt. % of slag relative to the weight of the flux. Embodiments may further include compounds providing one or more functions of surface cleaning, scavenging of impurities in the melt, and elemental additions to the superalloy.