Abstract: Methods and apparatus for plasma-assisted joining of one or more parts together are provided. The joining process may include, for example, placing at least first and second joining areas in proximity to one another in a cavity, forming a plasma in the cavity by subjecting a gas to electromagnetic radiation in the presence of a plasma catalyst, and sustaining the plasma at least until the first and second joining areas are joined. Plasma catalysts, and methods and apparatus for igniting, modulating, and sustaining a joining plasma, are provided. Additional cavity shapes, and methods and apparatus for selective plasma-joining, are also provided.

Abstract: Two silicon workpieces (20, 22) welded together into one member without the formation of cracks along the weld. It may be formed by a first method in which current (34, 36) is passed through one or both of the workpieces to heat them to between 600 and 900° C. Then an electric, laser, or plasma welder (38, 40) passes along the seam (24) between the workpieces to weld them together. In a second forming method, current (34) is passed through a plate (60), preferably formed of silicon, which either supports the workpieces or is brought into contact with at least one of them, whereby the workpieces are preheated prior to the welding operation.

Abstract: A method and system for fabricating electrical heating devices employing positive temperature coefficient (PTC) thermistor as heating elements which includes: assembling the heating devices with PTC thermistor heating elements preselected according to electrical resistance, applying pressure across the interface between the PTC heating elements and the radiator plates of the heating devices during their assembly, and exposing the heating devices for extended periods of time to both ambient and operational temperatures. The method of fabrication further includes continuously monitoring the electrical resistance of the heating devices and holding their electrical resistance stable by adjusting the pressure applied across the interface between the PTC heating elements and the radiator plates.

Abstract: A method and apparatus for sealing a package over/around a circuit is presented. A pressurized directional flow of plasma is applied between metal bonding edges of the package and a metal surface surrounding circuitry to be enclosed in the package. During the application of plasma between the bonding surfaces, a bonding devices direct contact fusion/diffusion bonds the metal bonding edges of the package to the metal bonding surface surrounding the circuitry to be enclosed.

Abstract: A method and apparatus for bonding a circuit component to a circuit package or board is presented. A pressurized directional flow of plasma is applied between attachment sites of the component to be bonded and the corresponding bond pad of the package/board. During the application of plasma between the bonding surfaces, direct contact fusion/diffusion bonds the component attachment sites to the corresponding bond pads.

Abstract: The invention provides a plasma welding or brazing process in which a direct current pilot arc is maintained throughout the process. The process comprises the steps of setting a pilot arc power supply (6) to a relatively high level, generating a high voltage spark discharge between a non-consumable electrode (14) of a plasma welding or brazing torch (2) and a nozzle (18) of said torch in order to start the flow of a pilot arc current, detecting the pilot arc current and reducing the pilot arc current to a relatively low level. The invention further provides apparatus for carrying out plasma arc welding, comprising a plasma welding torch, a controller and a power supply. The controller further comprises means for detecting the flow of a pilot arc current and or a main arc current and means for reducing this current on detection.

Abstract: Two silicon workpieces (20, 22) welded together into one member without the formation of cracks along the weld. It may be formed by a first method in which current (34, 36) is passed through one or both of the workpieces to heat them to between 600 and 900° C. Then an electric, laser, or plasma welder (38, 40) passes along the seam (24) between the workpieces to weld them together. In a second forming method, current (34) is passed through a plate (60), preferably formed of silicon, which either supports the workpieces or is brought into contact with at least one of them, whereby the workpieces are preheated prior to the welding operation.

Abstract: A method of fabricating an electrode is disclosed, wherein the electrode comprises a copper holder defining a cavity in a forward end. An emissive element and separator assembly is positioned in the cavity. An intermetallic compound is formed between the emissive element and the separator by heating a relatively non-emissive material until it melts and dipping the emissive element therein before cooling the assembly. As a result, the intermetallic compound is formed significantly faster than by conventional methods.

Abstract: A method and apparatus for bonding solid sheets together is presented. A modulated directional flow of plasma is applied at and between the bonding surfaces of the sheets to be bonded prior to and during the application of pressure to compress the bonding surfaces together to form a direct contact or diffusion bond.

Abstract: A method for plasma jet welding by means of a free radio frequency-induced plasma beam wherein, the rf-induced plasma beam is generated by a procedure involving a second process gas into a tube so that it has a tangential flow component and the introduction of the plasma through a metal expansion jet at the outlet.

Abstract: A method for closing and/or joining a connecting joint or joining seam between two pieces of galvanized sheet metal, in which zinc or a zinc alloy whose melting point is similar to that of zinc is heated to melting temperature and is continuously introduced into the connecting joint, with the heating being performed by a plasma jet without reaching the melting temperature of the steel sheet. The use of a plasma jet allows processing zinc or, a zinc alloy without producing any disturbing zinc spatter. The zinc can be supplied as a wire, powder or granulate, whereby it is introduced under an inert-gas bell. This method can also be employed for post-galvanizing weld seams, with a second plasma jet welding set following a first one, it being mechanically coupled with the same and performing the galvanizing of the weld seam by the supply of zinc in wire form without melting the steel sheet anew. Tin foils are used in a special embodiment which are applied in the joining zone of a flanged edge.

Abstract: A method and apparatus for bonding solid materials together is presented. A modulated directional flow of plasma is applied at and between the bonding surfaces of members to be bonded prior to and during the application of pressure to compress the bonding surfaces together to form a direct contact or diffusion bond.

Abstract: A method and apparatus for bonding solid plates together is presented. A modulated directional flow of plasma is applied at and between the bonding surfaces of the plates to be bonded prior to and during the application of pressure to compress the bonding surfaces together to form a direct contact or diffusion bond.

Abstract: An apparatus and method for producing an exhaust processor comprising: a clamping device for applying a predetermined clamping pressure to clamp a case or other component of the exhaust processor about a substrate or other component of the exhaust processor to define a gap between the case and substrate; a measuring device for measuring a size of the gap during application of the predetermined clamping pressure, the measuring device including a clamping pressure control system for adjusting the predetermined clamping pressure of the clamping device in response to the gap measurement so that the gap size is within a predetermined range; and a welder for welding a portion of the case component to an other portion of the caset when the gap size is within the predetermined range. The measuring device also includes a camera for measuring the gap size.

Abstract: A method for reducing or eliminating sagging in plasma arc keyhole welds adds a fluxing agent to the weld. The fluxing agent may be titanium nitride and/or titanium carbonitride. The fluxing agent is added using physical vapor deposition or by painting a slurry onto the weld surface.

Abstract: A near-surface defect in a nickel-base superalloy article having a nil-ductility range is weld repaired with a low-power, directional, spatially confined heat source. During the weld repair procedure, the body of the article is maintained at room temperature. Simultaneously, the surface of the article is locally melted in the region of the near-surface defect using the heat source to form a melted region, and thereafter the melted region is allowed to solidify. The heat source produces a shallow weld pool that allows the near-surface defect to be floated to the surface in the case of an inclusion, or welded closed in the case of a surface crack or near-surface void.

Abstract: A welding apparatus spot welds two or more overlapping sheets having a coating, such as zinc coated steel or aluminum alloy with an oxide coating. A hole is formed in the upper sheet at the desired point of spot welding. A clamping cup of a plasma arc passes surrounds the hole and contacts the upper surface of the upper sheet. The torch heats the sheet, allowing entrapped vapors in the coating on the lower sheet to vent freely. Filler wire is added to fill the hole and to secure the overlapping sheets together. If the overlapping sheets are zinc coated steel, preferably the filler wire is copper based.

Abstract: An object is to provide an optical fiber fusion splicing method in which splice loss can be reduced, and also to provide an arc-heating unit used for heating the fusion spliced part of an optical fiber. The method comprises a process of fusion-splicing together the end faces of two optical fibers and a process of continuously heating the fusion spliced part by arc while moving one pair of electrodes provided opposite to each other across the fusion spliced part. The arc heating process is performed with the operation for decreasing arc temperature.

Abstract: A method for reducing or eliminating sagging in plasma arc keyhole welds adds a fluxing agent to the weld. The fluxing agent may be titanium nitride and/or titanium carbonitride. The fluxing agent is added using physical vapor deposition or by painting a slurry onto the weld surface.

Abstract: A method for producing a lamp includes forming a tubular portion that is protruded in an end of an eyelet of a base of a lamp; drawing a lead wire for supplying power out of the tubular portion; and fusing the lead wire and the tubular portion with the eyelet by plasma arc welding. This ensures that plasma arc can be discharged to the protruded tubular portion, and therefore the tubular portion and the lead wire are fused with the eyelet of the base satisfactorily and stably. In the present invention, a tubular sleeve can be used in place of the tubular portion.

Abstract: A near-surface defect in a nickel-base superalloy article having a nil-ductility range is weld repaired with a low-power, directional, spatially confined heat source. During the weld repair procedure, the body of the article is maintained at room temperature. Simultaneously, the surface of the article is locally melted in the region of the near-surface defect using the heat source to form a melted region, and thereafter the melted region is allowed to solidify. The heat source produces a shallow weld pool that allows the near-surface defect to be floated to the surface in the case of an inclusion, or welded closed in the case of a surface crack or near-surface void.

Abstract: A method and apparatus for simultaneously cleaning and bonding a wire to a bonding surface is presented. In accordance with the invention, a gas is energized to form a plasma, which is then directed in a directional pressurized flow at the wire and bonding surface to form a dynamic plasma cleaning chamber bubble around the portion of the wire and bonding surface that are to be bonded together, and then the respective portions of the wire and bonding surface are bonded together within the plasma cleaning chamber bubble.

Abstract: Apparatus and methods for processing work piece components in which a molten phase is produced by a local energy input from at least one of an electric arc, a jet of combustible gas, an electron plasma, and a laser beam. At least one transducer is included for imparting oscillations having a frequency above 15 kHz. The oscillations can be imparted to one or more of the components, the region of the molten phase, and/or to any filler material that is added to the region of the molten phase. The apparatus and methods can be used with known thermal soldering, welding and cutting methods to improve the quality of weld beads and cut edges that are formed, and to increase the processing rate.

Abstract: A method and apparatus for welding together two silicon workpieces (20, 22) without the formation of cracks along the weld. In a first embodiment, current (34, 36) is passed through one or both of the workpieces to heat them to between 600 and 900° C. Then an electric, laser, or plasma welder (38, 40) passes along the seam (24) between the workpieces to weld them together. In a second embodiment, current (34) is passed through a plate (60), preferably formed of silicon, which either supports the workpieces or is brought into contact with at least one of them, whereby the workpieces are preheated prior to the welding operation.

Abstract: A combined laser and plasma-arc welding torch, which joins features of separate laser and plasma-arc welding devices in a single tool. A laser beam is directed by an optic system to be co-linear with the central axis of a plasma-arc torch. The laser beam passes through a group of electrodes, whose longitudinal axes are disposed at acute angle to the torch central axis on the generatrix of a cone, the apex of which lies on the torch central axis close to the section plane of a constricting nozzle, and the base of which faces the main body of the torch. The distance between the central axis and the closest point of the electrode is less than the laser beam radius in a section which is perpendicular to the central axis and passes through this closest point. The distal ends of the electrodes are provided with heat accumulating bulbs and mechanism for individual protection by delivering a separate gas. The electrodes may be cathodes both, anodes, or, cathodes and anodes.

Abstract: A method and apparatus for welding together two silicon workpieces (20, 22) without the formation of cracks along the weld. In a first embodiment, current (34, 36) is passed through one or both of the workpieces to heat them to between 600 and 900° C. Then an electric, laser, or plasma welder (38, 40) passes along the seam (24) between the workpieces to weld them together. In a second embodiment, current (34) is passed through a plate (60), preferably formed of silicon, which either supports the workpieces or is brought into contact with at least one of them, whereby the workpieces are preheated prior to the welding operation.

Abstract: A method for closing and/or joining a connecting joint or joining seam between two pieces of galvanized sheet metal, in which zinc or a zinc alloy whose melting point is similar to that of zinc is heated to melting temperature and is continuously introduced into the connecting joint, with the heating being performed by a plasma jet without reaching the melting temperature of the steel sheet. The use of a plasma jet allows processing zinc or a zinc alloy without producing any disturbing zinc spatter. The zinc can be supplied as a wire, powder or granulate, whereby it is introduced under an inert-gas bell. This method can also be employed for post-galvanizing weld seams, with a second plasma jet welding set following a first one, it being mechanically coupled with the same and performing the galvanizing of the weld seam by the supply of zinc in wire form without melting the steel sheet anew. Tin foils are used in a special embodiment which are applied in the joining zone of a flanged edge.

Abstract: A plasma arc welding apparatus having a coaxial wire feed. The apparatus includes a plasma arc welding torch, a wire guide disposed coaxially inside of the plasma arc welding torch, and a hollow non-consumable electrode. The coaxial wire guide feeds non-electrified filler wire through the tip of the hollow non-consumable electrode during plasma arc welding. Non-electrified filler wires as small as 0.010 inches can be used. This invention allows precision control of the positioning and feeding of the filler wire during plasma arc welding. Since the non-electrified filler wire is fed coaxially through the center of the plasma arc torch's electrode and nozzle, the wire is automatically aimed at the optimum point in the weld zone. Therefore, there is no need for additional equipment to position and feed the filler wire from the side before or during welding.

Abstract: An apparatus and method for producing an exhaust processor comprising: a clamping device for applying a predetermined clamping pressure to clamp a case or other component of the exhaust processor about a substrate or other component of the exhaust processor to define a gap between the case and substrate; a measuring device for measuring a size of the gap during application of the predetermined clamping pressure, the measuring device including a clamping pressure control system for adjusting the predetermined clamping pressure of the clamping device in response to the gap measurement so that the gap size is within a predetermined range; and a welder for welding a portion of the case component to an other portion of the caset when the gap size is within the predetermined range. The measuring device also includes a camera for measuring the gap size.

Abstract: A solid-solution strengthened superalloy weld composition, includes: about 10 to about 15 wt % Co; about 18 to about 22 wt % Cr; about 0.5 to about 1.3 wt % Al; about 3.5 to about 4.5 wt % Ta; about 1 to about 2 wt % Mo; about 13.5 to about 17.0 wt % W, up to about 0.08 wt % C; up to about 0.06 wt % Zr; up to about 0.015 wt % B; about 0.4 to about 1.2 wt % Mn; about 0.1 to about 0.3 wt % Si; and balance Ni.

Abstract: A method for locally heating objects, in particular thin sheet metal, by charging the objects by means of a plasma ignited between two electrodes. In order to keep the thermal stress of a subject as low as possible outside of the zone to be heated it is provided that the machining such as spot welding or burning through a breakthrough occurs with merely one plasma pulse which is produced by applying a voltage pulse exceeding the arc-over voltage of the gap between the electrodes.

Abstract: A radial bearing and method for making the same are disclosed. Radial bearings are typically used in downhole motors to control the direction of drilling in directional drilling operations. The cuttings from the bit are carried away by the drilling fluid and flow across the surfaces of the bearings before being removed from the well. The cuttings will contain sand and other hard and/or corrosive substances that will erode the surfaces of the bearings and shorten their useful life. The bearing of this invention is provided with a wear resistant surface to inhibit such erosion.

Abstract: Hybrid welding process and unit for welding metal workpieces, such as tailored blanks, by using a laser beam and an electric arc, preferably a plasma arc, in which process, after a welded joint has been produced, the laser beam is sent and/or deflected into radiation absorption means, such as an absorption cavity, allowing the radiation of the said beam to be absorbed. The beam continues to be deflected during the welding stop phase after producing one welded joint and before starting to weld a second welded joint. The process and the unit of the invention are particularly suitable for the mass production of workpieces for the motor-vehicle industry, such as tailored blanks that can be used to manufacture, for example, motor-vehicle body components, or for the mass production of pipes.

Abstract: A radial bearing and method for making the same are disclosed. Radial bearings are typically used control the direction of drilling in directional drilling operations. The cuttings flow across the surfaces of the bearings before being removed from the well. The cuttings will contain sand and other hard and/or corrosive substances that will erode the surfaces of the bearings and shorten their useful life. The bearing of this invention is provided with a wear resistant surface to inhibit such erosion. The bearing is made from a bearing blank to which is applied a first overlay of mild steel with dispersed cemented metal carbide pellets. The composition of the cemented metal carbide pellets is disclosed. The first overlay may be applied by any conventional technique. A second overlay of mild steel is applied to the first overlay utilizing a MIG welding process. As the second overlay is applied, a portion of the hard metal particles in the first overlay is dispersed in the weld puddle forming the second overlay.

Abstract: A material in powder or wire form on a nickel basis for the production of a coating with a high level of resistance to corrosion and wear by means of a thermal coating process is of the following composition (in percent by weight): C 0.005-1.0;  Cr 10.0-26.0; Mo  8.0-20.0; Fe  0.1-10.0; Si 3.0-7.0; B 1.0-4.0; Cu 0.1-5.0; Ni Balance. The material in powder form can be alloyed and sprayed out of the melt or agglomerated out of different alloyed and non-alloyed metal powders. The coating material can also be used in the form of a filling wire or an alloyed and cast bar material.

Abstract: A method and apparatus for simultaneously cleaning and bonding a wire to a bonding surface is presented. In accordance with the invention, a gas is energized to form a plasma, which is then directed in a directional pressurized flow at the wire and bonding surface to form a dynamic plasma cleaning chamber bubble around the portion of the wire and bonding surface that are to be bonded together, and then the respective portions of the wire and bonding surface are bonded together within the plasma cleaning chamber bubble.

Abstract: A method and apparatus for simultaneously cleaning and bonding a wire to a bonding surface is presented. In accordance with the invention, a gas is energized to form a plasma, which is then directed in a directional pressurized flow at the wire and bonding surface to form a dynamic plasma cleaning chamber bubble around the portion of the wire and bonding surface that are to be bonded together, and then the respective portions of the wire and bonding surface are bonded together within the plasma cleaning chamber bubble.

Abstract: This invention provides a method and apparatus for improved arc initiation during Gas-Metal Arc welding. The unstable period at the arc start is a period when increased spatter is produced and increased fume is generated and defects such as unacceptable weld bead profiles, porosity and inadequate penetration occur. It has been observed that initiating the arc using a substantially higher average arc current and thereafter switching the power supply to a CV mode for the remainder of the Gas-Metal Arc welding operation decreases the arc initiation period and the instability produced during this arc start period. Initiating the arc using a CC supply and then dynamically switching on-line the power supply to CV operation provides a means of decreasing the arc initiation period and the amount of instability produced during the arc initiation period. Power supplies for Gas-Metal Arc welding and other applications requiring on-line switching between CC and CV are disclosed.

Abstract: The invention relates to an automatic plant for cutting or welding by gas jet, especially by plasma jet, comprising a torch (T), a first pilot-gas line (L1), a second cutting- or welding-gas line (L2), control means (MP), first means (MR1) for adjusting the pressure of the pilot gas in the line (L1) and second means (MR2) for adjusting the pressure of the gas in the line (L2). The first adjustment means (MR1) are fitted in the line (L1) and controlled by control means (MP). A pneumatic control line (LP) pneumatically connects the line (L1) to the adjustment means (MR2) in order to enable the pressure of the cutting or welding gas to be adjusted in the second line (L2) on the basis of the pressure of the pilot gas in the line (L1), by acting on said second adjustment means (MR2).

Abstract: A method and apparatus for welding together two silicon workpieces (20, 22) without the formation of cracks along the weld. In a first embodiment, current (34, 36) is passed through one or both of the workpieces to heat them to between 600 and 900° C. Then an electric or plasma welder (38, 40) passes along the seam (24) between the workpieces to weld them together. In a second embodiment, current (34) is passed through a silicon plate (60) which either supports the workpieces or is brought into contact with at least one of them, whereby the workpieces are preheated prior to the welding operation.

Abstract: A plasma arc torch includes a housing having a nozzle at one end with a central orifice. An electrode extends into the orifice for producing a plasma arc. A port is disposed in the nozzle adjacent the orifice for injecting powder into the arc. The port includes an outlet, an inlet, and a reniform manifold extending therebetween for laterally distributing the powder about the nozzle orifice. In this way, the powder may be carried to the torch underwater and is distributed circumferentially about the plasma arc while simultaneously diffusing its carrier gas.

Abstract: A plasmagenic gas comprises a ternary mixture of helium, argon and hydrogen. The gas contains less than 30% helium, at least 55% argon, and from 5.5 to 15% hydrogen. The gas is energized to form a plasma. A powder of a refractory or metallic material is introduced into the plasma.

Abstract: A plasma arc welding for effectively letting gases of low boiling point substances for coating a steel sheet escape, ensuring the escape of a molten metal into gaps between the steel sheets and eventually accomplishing satisfactory plasma arc welding. A hole (31) is first bored in an upper sheet (21)(or both upper and lower sheets (21 and 22)) quickly by using a plasma arc (20) having greater power than an appropriate welding value, and a vapor of coating substances is allowed to escape through the hole (31). Subsequently, power of the plasma arc (20) is lowered to the appropriate welding value, and the upper sheet (21) and the lower sheet (22) are welded together while a filler (9) is being supplied to fill the hole (31) and the gap (23). While boring is made or immediately after boring is finished, the size of the gap (23) is measured on the basis of the plasma arc voltage, and the feed quantity of the filler (9) is controlled in accordance with the size of the gap (23).

Abstract: A method for locally heating objects, in particular thin sheet metal, by charging the objects by means of a plasma ignited between two electrodes. In order to keep the thermal stress of a subject as low as possible outside of the zone to be heated it is provided that the machining such as spot welding or burning through a breakthrough occurs with merely one plasma pulse which is produced by applying a voltage pulse exceeding the arc-over voltage of the gap between the electrodes (15′, 19′).

Abstract: In splicing optical fibers using an electric glow discharge generated between electrodes, the electric power in the glow discharge is maintained constant at varying ambient conditions, such as a varying atmospheric pressure. A signal representing the welding voltage is tapped at the middle terminal of a voltage divider circuit, and a signal representing the welding current is produced over a resistor. The signals are inputs to a multiplying circuit, the output signal of which is fed to one input of a comparator. A reference voltage is fed to the other input of the comparator. The error voltage from the comparator is an input signal to a control circuit providing a control signal to circuits for generating the voltage between the electrodes.

Abstract: A method of brazing, with the use of a plasma forming device (1) having a non-consumable electrode (2), comprises the following steps of operation. A first gas is supplied to said plasma forming device (1). A plasma flow is formed of said first gas by applying a voltage between said electrode (2) and an electrical terminal (7). The plasma flow is directed towards a work piece (7). Braze material (10) to be melted by said plasma flow is provided. Furthermore, a second gas may be supplied for shielding said plasma flow from the surrounding atmosphere. At least one of said first and second gas comprises a principal inert component including at least argon and in a minor amount an active component.