Showing papers on "Welding published in 1981"

Fracture mechanics studies of crack healing and welding of polymers

Abstract: Compact tension tests have been performed on re-healed and welded glassy polymers (PMMA-PMMA, SAN-SAN and PMMA-SAN). At temperatures above the glass transition temperature,Tg, it was observed that the facture toughness,KIi, in the interface increased with contact time,t, asKIi ∝t1/4 as predicted by a diffusion model. The self-diffusion constantD(Tg + 15 K) of chains of molecular weight 1.2×105 can be estimated as 1×10−21sec−1 with an activation energy of 274 kJ mol−1. For full material resistance, the depth of interdiffusion, 〈Δx2〉1/2, was calculated to be between 2 and 3 nm. Vacuum drying of the specimens, as well as polishing the interfaces, decreases the speed of interdiffusion.

Shock Waves and High-Strain-Rate Phenomena in Metals. Concepts and Applications.

Abstract: : The subject matter addressed by the chapters which compose this book is organized into nine sections followed by a number of appendices. Section 1 consists of a Historical Perspective followed by sections on High Strain-Rate Deformation, Dynamic Fracture, and Adiabatic Shearing (2,3,4). The next three sections deal with shock waves and constitute the core of the book: Shock Waves I: Experimental Techniques, Shock Waves II: Fundamentals, and Shock Waves III: Microstructural and Mechanical Effects, (5,6,7). The last two chapters treat the major applications: Dynamic Compaction of Powders (8) and Explosive Metal Working and Welding (9).

Weld quality monitor

Abstract: Weld arc voltage, weld arc current and weld arc travel speed are monitoredn a real-time basis during the welding process. Each monitored quantity or parameter is compared directly with a reference value indicative of a high quality weld, and an alarm is activated when a preselected variation in the measured and the reference quantities occurs. The monitored quantities are also used to calculate additional welding parameters, including heat input, weld bead area and cooling rate. These parameters are also compared to ideal reference values in order to control weld quality. The sensors used for measuring the welding parameters are selected so as to provide minimal interference with the welding process. For example, Hall effect transductors are used for current measurements, while a unique opto-electronic noncontacting sensor is used for measuring the weld speed.

Bottles with attached handles and a method of forming the same

Abstract: A plastic bottle with an attachable handle for lifting, carrying and pouring. The handle generally is L-shaped. One leg of the handle coacts with and is affixed to the neck of the bottle and the other leg coacts with the sidewall of the bottle. When the handle is attached, the one leg generally is horizontal and can be snapped on or otherwise affixed to the neck of the bottle, and the other leg generally is vertical and can be in engagement with or attached to the sidewall of the bottle by interlocking, welding, bonding, adhesive, banding or other means. Also, when attached the handle is positioned substantially within the breadth of the bottle. In forming the bottle and handle of the present invention, means can be provided for properly aligning the handle and bottle to facilitate coaction and attachment therebetween. In a preferred embodiment the present invention provides a large biaxially oriented pressurized bottle with a lifting, carrying and pouring attachable handle without impairing the desired shape and properties of the bottle.

The properties of stainless steel compacted dynamically to produce cold interparticle welding

Abstract: The impact of a high-speed punch on metal powder has been shown to result, under optimized conditions, in interparticle melting and welding. A strong compact is thus obtained which requires no subsequent thermal treatment. The technique can produce parts from non-equilibrium powders or powder mixtures. However, even with standard powder, such as stainless steel, the technique imparts unique properties to the resultant part. For instance, the macrohardness (420 HV) indicates an exceptionally high degree of work-hardening and that the interparticle melted zones are rapidly quenched. Annealing the compacts for 1 hour at temperatures up to 900° C does not result in a significant change in the yield stress.

Slag-metal equilibrium during submerged arc welding

Abstract: A thermodynamic model of the equilibria existing between the slag and the weld metal during submerged arc welding is presented. As formulated, the model applies only to fused neutral fluxes containing less than 20 pct CaF2, however some results indicate that the model may be useful in more general cases as well. The model is shown to be capable of predicting the gain or loss of both Mn and Si over a wide range of baseplate, electrode and flux compositions. At large deviations from the predicted equilibrium, the experimental results indicate considerable variability in the amount of Mn or Si transferred between the slag and metal phases, while closer to the calculated equilibrium, the extent of metal transfer becomes more predictable. The variability in metal transfer rate at large deviations from equilibrium may be explained by variations between the bulk and the surface concentrations of Mn and Si in both metal and slag phases.

Decorative light tubing

Abstract: Decorative light tubing, which has unbased miniature lamps connected in series by soldering or welding the ends of the flexible wire leads together to form parallel strings between a pair of elongated parallel wire conductors, is substantially filled with mineral oil or other clear, viscous dielectric fluid to protect the lamps and wiring against the adverse effects of vibration, shock and moisture while also enhancing the visual effect

Diaper and method of manufacturing the same

Abstract: 1. Process for a continuous manufacture of dispers comprising an absorbent pad arranged between a moisture-proof external cover and a permeable internal liner comprising the following steps : a continuous flexible sheet (2) of a moistureproof, heat-weldable material is unrolled ; a continuous elastic (7) in a stretched state is glued to at least the greater part of the length of the said sheet ; absorbent pads (3) of elongated shape are placed on the moisture-proof sheet (2) at uniform intervals, so that the lengthwise axis of the pads is perpendicular to the lengthwise axis of the said sheet ; a continuous liner (11) of a thin, moisture-permeable and heat-weldable material is unrolled onto the moisture-proof sheet provided with pads in this manner, so as to form a composite strip ; a plurality of openings (12) which are symmetrical relative to a transverse line (10) passing at right angles to both lengthwise edges, midway between the successive pads, are cut out from the said composite strip, between each two successive pads (3) between the two said edges ; the abovementioned composite strip is folded along a center lengthwise line (X-X) ; and the folded composite strip is severed along the abovementioned transverse line by a combined hot welding and cutting operation.

Arc welding simulator

Abstract: An arc welding simulator for instructional use includes a handpiece that supports a retractably mounted heat tube. The handpiece and heat tube are sized and shaped to resemble an actual electric arc welding apparatus, including an electrode. The simulator includes a drive mechanism for retracting the heat tube at a predetermined rate that simulates consumption of an actual arc welding electrode. A source of hot, pressurized air provides a stream of hot air through the heat tube. The simulator is used in combination with heat-sensitive paper that is preferably imprinted with a predetermined pattern resembling the pattern of movement that is followed during actual arc welding. A trainee uses the simulator by attempting to superimpose a thermal trace on the imprinted pattern. The resulting trace provides a permanent record of a trainee's success in tracking the imprinted pattern and correctly holding the simulator so as to maintain the tip of the heat tube positioned at a proper angle and distance with respect to the surface of the paper. In preferred embodiments of the welding simulator, a heating element is provided at the tip of the heat tube in combination with a small diameter air orifice tube so as to provide a narrow stream of heated air from the tip of the tube. Additionally, the simulator may be provided with a tilt switch and an acoustic alarm to alert the trainee when the simulator is moved from a predetermined angular position.

Method and apparatus for producing a composite material having ultrasonically welded seams which confine strands

Abstract: A composite material and a method for producing a composite material of a highly, multidirectionally elastic nature which includes ultrasonically welding an upper layer to a lower layer along substantially parallel, spaced apart weld seams, feeding elongated strands of an intermediate layer between the upper and lower layers and between the weld seams during the welding operation, and applying a tensile stress to at least one of the upper, lower and intermediate layers during the welding operation with such tensile stress being different from the tensile stress on at least another of the upper, lower and intermediate layers. Apparatus for performing the above method includes a plurality of spaced apart, disc-like anvil plates having circumferential teeth and fixedly secured to a common shaft for rotation therewith, an oscillating member disposed above the anvil plates for ultrasonically welding an upper layer to a lower layer along substantially parallel, spaced apart weld seams determined by the spacing of the anvil plates, feed tubes for feeding elongated strands of material of an intermediate layer between the upper and lower layers and between the weld seams during the welding operation, and a pair of rollers associated with each of the upper, lower and intermediate layers for supplying each of the respective layers to the anvil plates and for applying a variable tensile stress to the respective layers supplied to the anvil plates.

Magnetomechanical acoustic emission — a new method for non-destructive stress measurement

Abstract: This paper describes a newly found non-destructive testing technique for residual stress measurements, which is called magnetomechanical acoustic emission (MAE). It applies to ferromagnetic materials only, but has a greater depth of penetration than other common methods of residual stress analysis, such as X-ray diffraction and acoustic surface wave. Previous studies on MAE are reviewed, in which effects of metallurgical and magnetic parameters on MAE were evaluated. Our recent study has correlated magnetic properties of nickel and iron to MAE characteristics. Some of the observed features of MAe can be explained in terms of the domain theory, but many unresolved questions remain. Practical applications must await further developmental efforts, but some preliminary results of residual stress analysis for a welded steel plate and others are presented.

Vibrating screen with self-supporting screen cloth

Abstract: A plurality of truss-like supports are secured, as by welding, and in spaced relationship, to the underside of a screen cloth. The supported screen cloth is then removably secured in position in a vibrating frame to form therewith a vibrating screen. Each truss-like support includes a support rod formed of wire rod of predetermined diameter disposed with a major portion thereof spaced from and substantially parallel to the plane of the screen cloth, and with end portions thereof merging into the plane of the end pieces of selected wire rods forming the screen cloth and being welded thereto. A spacer wire, formed from wire rod of a diameter less than that of the support rod and to an approximate sinusoidal configuration, is disposed so that the upper tips, formed by the sine configuration, are welded to the bottom surface of the screen cloth and so that the lower such tips are welded to the upper surface of the support rod.

Low expansion laser welding arrangement

Abstract: An arrangement for laser beam welding wherein at least one of the components being welded is formed of a material which is substantially transparent to radiation at the wavelength of the laser welding beam. A layer of welding material is placed over the surface area of the weld joint, and is a type of material which is substantially absorbent of radiation at the wavelength of the laser welding beam. The welding material is then irradiated by the laser beam through the component which is substantially transparent thereto for a sufficient period of time to cause melting of the welding material and fusion thereof to the two components being welded. The present invention has particular applicability to welding with a Nd-YAG laser of components formed of silica-containing material, such as fused silica or titanium silicate, and wherein the welding material placed at the weld surface area is a titanium based material. The present invention is also particularly attractive for weld locations which are physically inaccessible to direct irradiation, but can be irradiated through the material which is substantially transparent to the laser welding beam.

Method of prefabricated construction, and building structure constructed in accordance with such method

Abstract: A method of construction by the use of prefabricated building units is described in which an open three-dimensional steel cage of relatively light structure is constructed off-site according to the desired specific configuration of the building unit; pre-cast concrete wall panels are attached to the sides of the steel cage by welding metal rings embedded within openings in the pre-cast concrete panels to laterally-projecting metal rings welded to the steel cage, to form the walls of the building unit and to add strength and rigidity to the building unit; the building unit is completed with a floor and roof further adding strength and rigidity to it; and the completed building unit is then transferred to a suitably prepared foundation at the construction site.

Image acquisition apparatus and process

Abstract: As apparatus for sensing reflected light patterns in the presence of a welding arc has an image-sensing means. Means is provided for directing one or more pulses of light of short duration at a workpiece. Each pulse has a peak intensity greater than that of the welding arc. A means is provided for blocking the light image from the sensing means except during a pulse from the light-directing means. An image sensing process includes the steps of directing light at the workpiece in one or more pulses, each of greater intensity than the welding arc. Light from the pulse reflected from the workpiece is sensed during the pulse, and sensing of light from the welding arc is blocked during the absence of a light pulse. This apparatus and process allows improved sensing of the light patterns in the presence of the welding arc and welding sparks.

Self-positioning welding or cutting torch

Abstract: A sensor for detecting the relative position of a workpiece with respect to the tip of a welding or cutting torch, which is movable in optional directions by positioning devices, is provided with a sensing body in annular form which surrounds the tip and is adapted to make contact with the workpiece on any side of the central opening of the sensing body. An arm is attached to the sensing body and is displaced in a direction and to a degree corresponding to the displacement of the sensing body. The displacement of the arm is detected and a signal corresponding to that displacement is generated to reposition the welding head in response to the signal.

Infrared Temperature Sensing of Cooling Rates for Arc Welding Control.

Abstract: : It is known that the weld metal mechanical properties of quenched and tempered steels are dependent upon cooling rate, which is presently indirectly controlled by specification of heat input. A method to directly control weld metal cooling rate would result in more consistency in achieving required mechanical properties. In the present investigation the use of commercial infrared sensing equipment was explored as a means of real-time monitoring of weld metal cooling rate. Infrared equipment has a distinct advantage over other temperature detecting systems in that it requires no physical contact with the work, thus affording a minimum amount of interference with the welding process, and is therefore a potentially useful detector for an adaptive feedback welding control system based on cooling rate. It was found that infrared thermography appears to offer considerable promise for welding control by providing weld metal cooling rates which are: (1) reproducible, (2) sensitive to variations in welding conditions, and (3) relatable to cooling rates as measured by plunged thermocouples. (Author)

Hard surfacing for a centrifuge conveyor.

Abstract: A centrifuge conveyor (14) is provided with improved hard surfacing wherein unitary subassemblies of backing tiles (26X) and wear-resistant members (28X)are welded by the backing tile (26X) to the conveyor (14) A subassembly is made unitary by the interengagement of the wear-resistant member (28X) to an undercut groove in the backing tile (26X) and by bonding with a heat reactive adhesive (300) or grout applied to the interengaging parts Each fragile wear-resistant member is braced against deflection at its outer portion through its backing tile to the conveyor The preferred embodiment employs a plurality of wear-resistant members per backing tile, each such member being accurately pressed to its intricate, interlocking shape from sintered tungsten carbide

Color picture tube

Abstract: PURPOSE:To gain a color picture tube in which a close contact heaping of a contact spring is prevented and a drop down of the contact spring owing to a weak welding is avoided, by forming projections at the plane portion of the contact spring. CONSTITUTION:A contact spring 7 is formed with a frame fixing member 7a to fix to a mask frame 2 at one end, a funnel contact member 7b of a circle arc form to contact to a funnel at the other end, and a connecting member 7c between the frame fixing member 7a and the funnel contact member 7b. At the frame fixing member 7a is formed a projection 7d projecting at the opposite side of the mask frame 2, and at the connecting member is also formed a projection 7e. These projections 7d and 7e are made at the same time as the contact spring 7 is made. Therefore, the close contact heaping of the contact spring 7 is prevented, always only one spring is spot-welded 8 to the mask frame 2, and a trouble that the contact spring drops down owing to a weak welding is avoided.

Weld line structures and properties in injection molded polypropylene

Abstract: Weld regions are formed wherever polymer flow fronts meet. The present study examines the effects of melt temperature, mold temperature, mold cooling conditions, injection speed and annealing on the tensile properties and morphological structure of weld regions in four commercially available polypropylene resins. One of the resins contained nucleation particles. Scanning electron micrographs of the weld region revealed a wide range of morphologies from very strong welds which formed part of a stable neck to brittle failures at low elongation caused by the presence of large nucleation particles in the weld region. The melt temperature, mold temperature, and annealing had the greatest effect on the weld region's tensile properties.

Mechanically laying reinforcements for laminated components - using machine which winds unidirectional layers of filaments for subsequent bonding and cure

Abstract: Reinforcement system for flat or similar shape components or laminates consists of filaments which are laid to and fro in closed configurations to suit requirements, they are deposited as at least one layer covering the whole area and are bonded together either by pre-impregnating with resin and/or pre-bonding or by laying transverse adhesive strips, welding filaments, sewn threads, woven threads, etc. Reinforcement patterns are laid/orientated exactly to suit requirements, their filaments do not cross each other in a woven manner, numerous fibres are suitable (e.g. glass, carbon, polyester).

Process and apparatus for converged fine line electron beam treatment of objects

Abstract: This disclosure is concerned with the use of fine line converged electron beams of high aspect ratio for effecting physical, chemical, mechanical and other changes in the surface of objects, and also volume effects, including applications, for example, to semiconductor and other materials surface modification technology, annealing, welding, etching, polishing, cutting, curing and other surface and volume alteration

Laser welding method

Abstract: PURPOSE:To fill perforated holes thoroughly with molten metal and to prevent the formation of blowholes by subjecting iron and steel materials to be welded to laser welding by using shielding gases consisting of inert gases mixed with suitable amts. of active gases according to the kinds of said materials. CONSTITUTION:Iron and steel materials to be welded are subjected to laser welding by using shielding gases consisting of inert gases such as argon and helium mixed with suitable amts. of active gases such as oxygen, nitrogen and carbon dioxide according to the kinds of said materials. For example, if the materials to be welded are carbon steel, low alloy steel, high tensile steel, martensitic stainless steel and ferritic stainless steel, the shielding gases consisting of the compsns. of TableIare used. If the materials to be used are austenitic stainless steel, the shielding gases consisting of the compsns. of Table II are used. Thus the formation of babbles in molten metal is prevented in welding.

Circuit for electro mechanical tubing sealer

Abstract: A pair of jaws moveable with respect to one another whether mounted in a hand held sealer or desk mounted sealer, compresses, heats, elongates, spreads and welds liquid filled tubing placed therebetween. Variants of the pair of jaws provide means for serially or simultaneously segmenting the tubing into a plurality of sealed compartments. The pair of jaws are electrically connected to a source of RF energy as the plates of a variable capacitor in an RF resonant circuit. The flow of RF energy across the pair of jaws, which energy heats the tubing and, in conjunction with mechanical pressure, makes the weld, is a function of timing and of the spacing between the jaws which spacing affects the degree of resonance of the RF resonant circuit. Simultaneous with the heating of the tubing, the configuration of the pair of jaws compresses the tubing placed therebetween and focuses the RF energy in a narrow swath across the tubing while simultaneously elongating and spreading the tubing at the swath to obtain a leak free weld, which weld is configured to provide for separation of the sealed compartments without tearing or rupturing the compartments.

Remote control for welding machine amperage

Abstract: A solenoid operated, ratchet-type step motor incrementally advances the rheostat of a welding apparatus in opposite directions to control welding current. The solenoids are pulsed in response to reception of a frequency and digitally coded radiant energy signal by a receiver to which signals are transmitted from a remote transmitter having direction selecting push button switches.

System and method for impact welding by magnetic implosion

Abstract: A system for impact welding using an electrical coil producing a magnetic field of sufficiently high-intensity to impel a ballistic workpiece into a separate stationary workpiece for producing a weld therein. The pressure on the ballistic workpiece resulting from the magnetic repulsion between the ballistic workpiece and the coil results in the ballistic workpiece being propelled towards the stationary workpiece at sufficient velocity to form a weld. Parameters are provided for varying the voltage and inductance of the capacitor bank for particular driving coil and ballistic workpiece dimensions to obtain matching of the impedances of the capacitor and coil arrangement to the particular ballistic workpiece. The impedance matching maximizes the conversion of electrical energy in the bank to kinetic energy of the workpiece.

Non-destructive inspection by frequency spectrum resolution

Abstract: A method of inspecting non-destructively a specimen for examining presence or absence of a defect in the specimen, in which an ultrasonic wave is emitted from a probe (2) and a reflected wave from the specimen (1) is received by the probe (2) whose output signal is processed to determine the presence or absence of the defect. The signal processing includes steps of extracting characteristic parameters from a frequency spectrum of the ultrasonic echo and comparing the extracted parameter with corresponding experimentally or theoretically determined value. The invention makes it possible to automatically determine discriminatively whether the reflector of the ultrasonic echo is a configured portion, a weld boundary or a defect of a specimen to be inspected.

Process and apparatus for making a welding sleeve

Abstract: A welding sleeve useable for connecting of pipes formed from thermoplastic material, is formed from a tubular body of thermoplastic material and a coil disposed on its inside surface. The coil has a resistance wire encased with thermoplastic material. The windings of the coil (4) are bonded into a compact coil which is inserted into the heated tubular body while it is simultaneously widened. As the result of a partial contraction of the tubular body also of the coil a firm connection develops between the oil and the body. Furthermore, the tubular body has a frozen-in, latent, radial contraction strain as a result of the widening, which during heating during the welding process, eliminates the radial play between coil and the pipes and produces a welding pressure.

Welding apparatus for motorcar body

Abstract: Welding apparatus for a motorcar body comprising a pair of welding jig units positioned on opposing sides of a combining station which are movable laterally for positioning and holding thereon side panels of the body and a carrier movable between the combining station and a setting station for positioning and holding thereon the floor panel and the roof panel of the motorcar body. The structures of the carrier and the welding jig units are disclosed. Each welding jig unit can be turnable between an inwardly facing position and an outwardly facing one.