Abstract:
A containerless method of producing a crack free metallic article of near-net shape includes melting a filler material into a metallic substrate or seed under conditions chosen to preclude cracking. In a preferred embodiment of the invention, a laser beam is operated at a relatively low power density and at a relatively large beam diameter at the substrate surface for an extended length of time to produce a molten pool with a low aspect ratio. Near-net shape is achieved by applying the process in a closed-loop, multi-axis material deposition system.
Abstract:
A method of producing a coating layer on a localized area of a superalloy component comprises the steps of:a) producing a coating layer element with specific functional properties;b) depositing on at least one surface of the coating layer element a uniform layer obtained from a powder mixture consisting of a powder of a nickel or cobalt superalloy and a powder of a brazing filler metal;c) brazing the coated composite coating layer element obtained from step (b) on to the localized area of the component; and,d) machine finishing the component.
Abstract:
A method and apparatus are provided for hardsurface cladding a workpiece such as a tip shroud notch face of a turbine bucket configured for contact engagement with an adjacent tip shroud notch face. A continuous wave laser beam is generated in a Nd:YAG laser and directed on the notch face at a spot to provide heat thereat. A hardsurface cladding wire is dispensed at the spot under a shielding gas for being melted by the laser beam to form a molten cladding layer on the notch face. The laser beam and wire are traversed over the notch face to form a cladding layer over the entire notch face, which is cooled and solidified in a hardsurface cladding layer integrally bonded to the notch face.
Abstract:
A linear friction welding process provides two members to be joined together into a final product, where each of the members has a major outer surface, where one of the two members is a stub which is surrounded, at least in part, on its outer major surface by a collar. The stub is generally restrained without substantial restraining contact on its outer major surface by tooling, thereby eliminating the risk that tooling will cause physical or chemical damage to the final shape. Thereafter, pressure and relative movement are applied between said members to linear friction weld the members together. A collar comprises a major inner surface surrounding a portion of a major outer (lateral) surface of a member to be linear friction welded, and further comprises a radially outer surface which extends a surface to be interfaced of the member. The collar has an outer lateral surface which may be curved in order to prevent stress and cracking of the collar during linear friction welding. The inner and outer lateral collar surfaces may be generally parallel to each other, making the area of the outer radial surface of the collar small, so that less process input energy is needed to overcome the friction contributed by the collars, and so that the collars experience smaller loads during linear friction welding, making them easier to secure.
Abstract:
A device exists for translational friction welding of a first component and a second component. The device includes a holder to hold the first component within an open ended frame having an open space within for receiving the first component. The frame includes a base and transversely spaced apart first and second members which longitudinally extend from the base to an open end of the frame at which is located a clamping feature used to clamp the first component in the holder with a clamping force having force components oriented along three orthogonal axis and has opposing tapering pressure surfaces which open outwardly in a first direction and taper inwardly in a second direction which is perpendicular to the first direction. A sacrificial block on the second component has block ends with surfaces that conforms to the surfaces of one of the clamping features. In a preferred embodiment the clamping feature is a compound wedge shaped notch and the block ends have corresponding compound wedge shapes.
Abstract:
A process and apparatus is provided for laser welding a nickel and/or cobalt based superalloy article comprising: preheating the entire weld area and adjacent region to a ductile temperature with an induction heat coil and maintaining such temperature during welding and solidification of the weld; and welding the preheated article utilizing a laser with a powder alloy feed with a control means controlling the laser, power feed and motion system on which the article is fixtured, wherein the control means includes a vision system which digitizes the weld area providing a path for the laser welding to follow.
Abstract:
A component holder for a friction welding apparatus has upper and lower clamp members which can be urged towards each other in order to clamp between them a component to which second or further components are to be friction welded. The first component is held in the component holder substantially entirely by friction clamping forces. The component holder is particularly suited to use with friction welding apparatus in which the component holder is carried by an angularly reciprocable workpiece mounting member.
Abstract:
A process and apparatus are provided for separating components of a brazed vane assembly by preheating the assembly to a temperature below the solidus of the base metal of the vane assembly and above the liquidus of the braze, then maintaining such temperature while separating the airfoil from the platform by pulling/pushing the airfoil and platform apart.
Abstract:
Method is for assembling a disk fitted with small wings. The small wings are composed of a foot made of an element with the disk and welded blades. The disk and the blades are installed on a rotating template with fixing means in the desired position and elements are merged at the joining surface by an electron gun or similar device. The small wings are successively welded during one or two operations. Screens for halting heating radiation are situated behind the wings to be welded. Rotors of turbines and compressors may be assembled in this manner.
Abstract:
A method is described for the separation of metal articles from surplus metal by the use of a laser. The articles may be cast or wrought. Several examples are given of gas turbine engine components being separated from a gating system by the use of a YAG laser. Benefits include lack of heat generation and, therefore, little or no distortion in the article.