General Electric Company

Herman A Nied

Robert E Sundell

Mark Gilbert Benz

Marshall Gordon Jones

Michael R Eggleston

Melvin Robert Jackson

Robert John Zabala

Hsin-Pang Wang

Stanley J Godwin

Robert K Cohen

Robert V Klint

Radhakisan S Baheti

A new method for forming a joint between a molybdenum-based alloy structure and a structure formed from a more ductile alloy is disclosed. The method involves the solid-state bonding of the two structures, which can be carried out by a variety of techniques, such as inertia-welding or explosive-welding. The molybdenum-based alloy may be a TZM-type material, while the more ductile alloy may be tantalum-based, niobium-based, or nickel-based, for example. This method is especially useful in the manufacture of x-ray devices, such as those which include rotary anode assemblies. As one illustration, the method can be used to provide a very strong joint between a target formed from a molybdenum alloy and an insert formed from a tantalum alloy. Related x-ray assemblies are also described.

Method for connecting a molybdenum-based alloy structure to a structure

A brazing process is enhanced by the employment of an external electromagnetic field. In complex joints of large components, gravity and surface tension forces acting on the molten braze alloy are insufficient for completely filling the interfacial gap. An external electromagnetic field enhances molten braze flow into voids between the components.

Electromagnetic field enhanced brazing method

Electric resistance welding provides localized heating for simultaneous upset welding of the copper bars and copper end rings of an electric motor cage rotor assembly. Rapid application of an axial force completes the upset welds. The localized heating is in high current, low voltage pulses for which a homopolar welding generator is utilized.

Electric resistance welding of electric motor cage rotor assemblies

An improved high performance x-ray system having a rotating anode therein which includes an improved target/stem assembly comprising a metallic target and a large bore, thin-walled tubular metal stem which, when connected to a rotor body assembly, provides a rotating x-ray tube anode assembly is disclosed. An insert of an alloy, for example, tantalum alloy, is placed between the target layer and the large bore, thin-walled tubular niobium or niobium alloy stem and then bonded thereto to produce a composite x-ray tube target/stem assembly. The target/stem assembly is then connected to a rotor body assembly by fasteners, preferably threaded, to produce a rotating anode assembly having high bond strength that provides acceptable balance during x-ray tube operations.

Target/rotor connection for use in x-ray tubes

Methods of making an improved high performance x-ray system having a rotating anode therein which includes an improved target/tubular stem combination which, when combined with a rotor body assembly, reduces tube failure due to anode assembly imbalance and methods of bonding a metallic target and a metal tubular stem and connecting the combination to a rotor body assembly to provide a rotating x-ray tube target are disclosed. An insert of an alloy, for example, tantalum or its alloys, is placed between the target and the niobium-alloy tubular stem and then bonded thereto to produce the x-ray tube target/tubular stem assembly having a high remelt temperature and bond strength which, when connected, such as by bolting to the rotor body assembly, the resulting anode assembly retains proper balance during x-ray tube operations.

Method of making an improved target/stem connection for x-ray tube anode

This invention relates to butt joining methods. Such methods of this type, generally, allow fiber reinforced metal matrix composite components having a metal matrix and a fiber reinforcement to be butt joined in order to form a large integral structure.

Method for fiber reinforced composite butt joining

This invention relates to the solid state joining of metal alloy pieces in order to form an integral structure. Such structures of this type, generally, allow the metal alloy pieces to be joined by local interfacial strain control.

Metal alloy solid state joining by local interfacial strain control

In order to control the cooldown temperature of a weld produced by a friction welding process, an electrical signal having a low voltage and a high current is passed through the weld thereby providing desired metallurgical properties. The weld acts as a resistor due to its high temperature as compared to the surrounding material such that the current causes the weld to heat up when the current passes through the weld and also causes the electrical signal to change as it passes through the weld. The change in current can be measured and the temperature of the weld can be controlled which allows the cooldown of the weld to be properly maintained for the desired metallurgical properties.

Concurrent friction/joule heating weld process

In order to determine the temperature of a weld produced by a friction welding process, an electrical signal having a low voltage and a low current is passed through the weld. The weld acts as a resistor due to its high temperature as compared to the surrounding material such that the current in the electrical signal changes after its interacts with the weld. The change in current can be measured and the temperature of the weld can be determined.

Friction welding temperature measurement and process control system

Fiber optic laser apparatus for spot welding, brazing, or soldering comprises an optical fiber for transmitting a laser beam to a workpiece, and a tool disposed at an output end of the optical fiber for mechanically engaging and applying pressure to the workpiece. The output end of the optical fiber is supported within a longitudinal bore of the tool with the tip of the fiber closely adjacent to an opening in a workpiece-engaging end of the tool. The diverging laser beam from the end of the optical fiber projects a spot onto the workpiece through the opening with sufficient power to cause melting without the necessity for a lens system for focusing of the laser beam.

Fiber optic laser joining apparatus

A robotic arc welding system has an integrated vision sensor to image and analyze the weld scene in real time. The most effective weld puddle geometry discriminants for use in an adaptive feedback control, to assure full penetration welds, are weld puddle area and maximum width. The adaptive control system determines a puddle geometry error and a correction to nominal welding current to change the heat input to the weld pool, regulating a combination of puddle area and width, or only puddle area under some welding conditions, to control weld quality during the welding process. Arc voltage is modulated to reflect changes in welding current and maintain constant arc length.

Arc welding adaptive process control system

A multivariable process monitor and method of monitoring a resistance spot welding process to yield instantaneous information on weld quality during the weld cycle. Sensors on the machine measure welding input variables and workpiece response variables and provide signals to a microcomputer system. A simplified analytical model of the spot welding process is incorporated in the microcomputer and is the reference for the weld quality logic that accepts or rejects the weld. Faulty welds are diagnosed and the reason displayed.

Resistance spot welder process monitor

A composite electrode configuration prevents mushrooming of resistance spot welding electrodes due to local high contact pressure and current densities. For a truncated electrode, an outer sleeve of high strength and high electrical resistivity material is attached to the end of the electrode and takes the high contact stress at the edge of the flat end face. A spherical end electrode has a plug of higher strength material in the center where the highest contact stress exists, and the outer sleeve reduces the joule heating effect. A transverse insulating spacer is a thermal and electrical barrier.

Composite resistance spot welding electrode

An instrumented spot welding electrode significantly improves the weld quality available from production resistance spot welding machines by providing real time measurements of key multivariable resistance welding parameters. The real time data provided may be used as inputs to adaptively control welding machines and dynamically adjust welding system operation responsive to the sensed variables. A number of sensors are positioned within a cavity specially formed into a water cooled electrode tip to obtain the desired measurements while being protected against physical damage. The sensors are advantageously placed in good thermal and electrical contact with a plug element which bears directly on the workpieces being welded to enhance the accuracy of the sensed variables. This specially configured and instrumented sensor cavity is ideally suited for use with all end types of electrodes including spherical, truncated, offset, flat and the like.

Instrumented spot welding electrode

The thickness of the molten weld nugget is continuously monitored during resistance spot welding, and when proper penetration is achieved the applied current is turned off. An ultrasonic transducer housed in the water cooled lower welding electrode transmits ultrasonic pulses into the workpiece and receives waves reflected at each solid/solid and liquid/solid interface. The position of the latter is tracked by pulse time discrimination of reflected signals; weld nugget penetration is computed using a ratio of times or a pulse time difference.

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Ballston Lake, NY, United States of America

Herman A Nied