Abstract:
USING MAGNETIC FORCE UPSET WELDING TO FORM T-JOINTS BETWEEN DISSIMILAR THICKNESS PARTS. THIS TYPE OF RESISTANCE WELDING IS USED TO JOIN COMPRESSOR AND TURBINE PARTS THEREBY REDUCING THE WEIGHT AND COST OF A JET ENGINE.
Abstract:
1,114,458. Welding by pressure. CATERPILLAR TRACTOR CO. 25 Nov., 1965 [3 Dec., 1964], No. 47418/65. Heading B3R. In bonding metal parts which comprise material which can precipitate a hard, brittle intermetallic compound, e.g. a carbide, ends of the parts are engaged in rotational rubbing contact under pressure, the initial speedof relative rotation and the total energy employed are restricted to minimize precipitation of substantial amounts of the compound and the bond zone is worked plastically at low speeds as the bond forms to shatter and disperse compound which does precipitate. A nickel base superalloy turbine wheel 12, Fig. 1, and a carbon steel shaft 13, the alloy and carbon steel containing sufficient carbon and carbide forming elements to precipitate carbides are friction welded at initial outer edge speeds of 400 and 265 feet per minute using a flywheel means to store the required energy and expend it all in making the weld, a small amount of carbide being formed at 400 ft. per minute and eliminated at 265 ft. per minute. The lower speeds require a greater flywheel mass which makes a large part of the stored energy available for low speed plastic working of the bond zone as the bond forms. The inside diameter of the lower strength shaft is less than that of the turbine wheel and the outside diameter is greater to produce a larger end face on the lower strength part to prevent excessive flashing away thereof. The nickel base super alloy and carbon steel may be welded using initial outer edge speeds of 150-400 ft. per minute and a cobalt base " Stellite " alloy (Stellite is a Registered Trade Mark) and carbon steel may be welded using initial outer edge speeds of 150-350 ft. per minute.
Abstract:
The present invention provides a brazing fixture and method of using the fixture which allows the brazing of a joint in an oxide-dispersion-strengthened (ODS) high temperature alloy workpiece where stresses in the workpiece operate to open the joint during the brazing process. The fixture is formed from the same ODS alloy as the workpiece, such that the fixture exhibits the same coefficient of thermal expansion as the workpiece. This allows maximization of surface area contact between the fixture and the workpiece during the brazing operation in order to force the workpiece to maintain its design dimensions and to prevent the joint from opening. The fixture includes a cavity preventing fixture/workpiece contact in the area of the braze to help control thermal lag in the area of the joint.
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 for applying a material to the face 16,18 of a rotor blade 10 is disclosed. The method includes blocking the flow of molten material to adjacent structure of a rotor blade by disposing a pad against the structure.
Abstract:
A fabricated gas turbine engine component and method of manufacturing. In one embodiment the component having a structural member with a cover member metalurgically bonded thereto. The bonding of the cover member being controlled by an apparatus that sequentially applies a substantially non-unifrom bonding load across the components radius of curvature. The patterns utilized in the casting process are formed in one embodiment to a precision preformed geometry by a closed die forming operation.