Showing papers on "Electric resistance welding published in 2002"

The welding of aluminium and its alloys

Abstract: Introduction to the Welding of Aluminium. Welding metallurgy. Material Standards, Designations and Alloys. Preparation for Welding. Welding Design. TIG Welding. MIG Welding. Other Welding Processes. Resistance Welding Processes. Welding procedure and welder approval. Weld Defects and Quality Control. Appendices.

A unified numerical modeling of stationary tungsten-inert-gas welding process

Abstract: In order to clarify the formative mechanism of weld penetration in an arc welding process, the development of a numerical model of the process is quite useful for understanding quantitative values of the balances of mass, energy, and force in the welding phenomena because there is still lack of experimentally understanding of the quantitative values of them because of the existence of complicated interactive phenomena between the arc plasma and the weld pool The present article is focused on a stationary tungsten-inert-gas (TIG) welding process for simplification, but the whole region of TIG arc welding, namely, tungsten cathode, arc plasma, workpiece, and weld pool is treated in a unified numerical model, taking into account the close interaction between the arc plasma and the weld pool Calculations in a steady state are made for stationary TIG welding in an argon atmosphere at a current of 150 A The anode is assumed to be a stainless steel, SUS304, with its negative temperature coefficient of surface tension The two-dimensional distributions of temperature and velocity in the whole region of TIG welding process are predicted The weld-penetration geometry is also predicted Furthermore, quantitative values of the energy balance for the various plasma and electrode regions are given The predicted temperatures of the arc plasma and the tungsten-cathode surface are in good agreement with the experiments There is also approximate agreement of the weld shape with experiment, although there is a difference between the calculated and experimental volumes of the weld The calculated convective flow in the weld pool is mainly dominated by the drag force of the cathode jet and the Marangoni force as compared with the other two driving forces, namely, the buoyancy force and the electromagnetic force

Laser Transmission Welding of Semi-Crystalline Thermoplastics—Part I: Optical Characterization of Nylon Based Plastics

Abstract: Optimization of welding for thermoplastic parts strongly depends on the material properties, part design, as well as the welding operating technology conditions. Laser transmission welding requires...

Apparatus and method for forming weld joints having compressive residual stress patterns

Abstract: The welding apparatus (100) and associated method are provided. The welding apparatus includes a welding tool (102) for forming a weld joint (28) along the surface of at least one workpiece (12). The welding apparatus also includes a compression tool (106) for selectively inducing a layer of residual compressive stress in at least a portion of the surface of the weld joint and the surface of the at least one workpiece to thereby improve the material properties of the workpiece, including corrosion resistance and fatigue strength.

Welding stability assessment apparatus for pulsed arc welding

Abstract: The present invention relates to an apparatus for assessing start-of-weld and steady state welding stability in pulsed arc consumable electrode gas-shielded welding. According to the present welding stability assessment apparatus, in order to obtain a pass/fail decision on start-of-weld welding stability for pulsed arc welding, an irregularity value is computed by a computer means, based on detected values from a detector means; and a pass/fail decision is made by an assessment means, thus making it possible to perform accurate assessment of start-of-weld welding stability in pulsed-arc welding.

Arc welding quality evaluation apparatus

Abstract: An arc welding quality evaluation apparatus for consumable electrode gas shielded arc welding comprises a heat input detection means 8 for detecting heat input applied to a workpiece to be welded; a welding time detection means 11 for detecting the welding time of the workpiece; a spatter weight detection means 16 for detecting the weight of spatter produced during the welding time of the workpiece; a heat compensation means 17 for compensating for heat loss due to spatter occurring during the welding time of the workpiece; an effective heat input computation means 12 for computing effective heat input per unit welding time, based on detected values of the detection means 8 and 11, and a compensation value of the heat compensation means 17; and a weld quality assessment means 22 for comparing an output of the effective heat input computation means 12 to a reference standard value, and assessing weld quality acceptability based on the degree of separation of the computation means output from the reference standard value.

Interlaminar contact development during thermoplastic fusion bonding

Abstract: Fabrication of layered thermoplastics and thermoplastic-matrix composites using processes such as tow placement, tape laying, and resistance welding is fundamentally based on the principle of fusion bonding, which involves applying heat and pressure to contacting thermoplastic surfaces One of the important processing steps-intimate contact development-is considered in this paper Interlaminar intimate contact development has a strong dependency on the thermoplastic surface geometry Profilometric measurements of common thermoplastic prepreg tows, such as AS4/PEEK and IM7/PIXA, show that surface roughness features appear at several length scales and that the surfaces have fractal asperity structures In this paper, principles of fractal geometry are used to describe prepreg surfaces Based on this description, a microscale fluid flow model is developed to relate a degree of intimate contact to the process parameters (pressure, temperature, and time) and the fractal parameters of the surface The model development and comparisons with experimental data are presented and discussed

Laser welding of aluminium alloy 5083

Abstract: There are two laser welding mechanisms, keyhole mode and conduction mode. Keyhole welding is widely used because it produces welds with high aspect ratios and narrow heat affected zones. However keyhole welding can be unstable, as the keyhole oscillates and closes intermittently. This intermittent closure causes porosity due to gas entrapment. Conduction welding, on the other hand, is more stable since vaporisation is minimal and hence there is no further absorption below the surface of the material.Conduction welds are usually produced using low-power focused laser beams. This results in shallow welds with a low aspect ratio. In this work, high-power CO2 and YAG lasers have been used to produce laser conduction welds on 2mm and 3mm gauge AA5083 respectively by means of defocused beams. Full penetration butt-welds of 2mm and 3mm gauge AA5083 using this process have been produced. It has been observed that in this regime the penetration depth increases initially up to a maximum and then decreases with increasing spot size (corresponding to increase in distance of focus above the workpiece). Results of comparison of tensile strength tests for keyhole and conduction welds are shown.This process offers an alternative method of welding aluminium alloys, which have a high thermal conductivity.There are two laser welding mechanisms, keyhole mode and conduction mode. Keyhole welding is widely used because it produces welds with high aspect ratios and narrow heat affected zones. However keyhole welding can be unstable, as the keyhole oscillates and closes intermittently. This intermittent closure causes porosity due to gas entrapment. Conduction welding, on the other hand, is more stable since vaporisation is minimal and hence there is no further absorption below the surface of the material.Conduction welds are usually produced using low-power focused laser beams. This results in shallow welds with a low aspect ratio. In this work, high-power CO2 and YAG lasers have been used to produce laser conduction welds on 2mm and 3mm gauge AA5083 respectively by means of defocused beams. Full penetration butt-welds of 2mm and 3mm gauge AA5083 using this process have been produced. It has been observed that in this regime the penetration depth increases initially up to a maximum and then decreases with incr...

Fusion Bonding of Polymer Composites

Abstract: 1 Introduction- 11 Advanced Thermoplastic Matrix Composites (TMPCs)- 12 Joining Technology for Composite Materials- 13 References- 2 The State of the Art in Fusion Bonding of Polymer Composites- 21 Introduction- 22 Traditional Technologies- 221 Mechanical Fastening- 2211 Bolted/Riveted Joints- 2212 Integral Fit Joint Technology- 222 Adhesive Bonding- 223 Solvent Bonding- 23 Fusion Bonding Technology- 231 Introduction- 232 Fusion Bonding Techniques- 2321 Bulk Heating- 2322 Fractional Heating- 2323 Electromagnetic Heating- 2324 Two-stage Techniques- 24 Joining of Dissimilar Materials- 241 Introduction- 242 Metal Substrates- 2421 Surface Preparation- 2422 Fusion Bonding of TPMCs and Metal Substrates- 243 TSMC Substrates- 2431 TP Hybrid Interlayer- 2432 TP Film Co-cure- 25 Comparative Assessment- 251 Joint Performance- 2511 Strength- 2512 Durability- 252 Process Performance- 2521 Cost and Processing Time- 2522 Quality- 2523 Suitability to Automation/Production Environment- 2524 Minimal Surface Preparation- 253 Process Adaptability- 2531 Flexibility- 2532 Large-scale Joining- 2533 Portability/Application to Repair- 254 Environmental Aspects- 2541 Reprocessing/Recycling- 2542 Environmental Friendliness- 26 Concluding Remarks- 27 References- 3 Heat Transfer in Fusion Bonding- 31 Introduction- 32 Heat Generation- 321 Ultrasonic Welding- 322 Induction Welding- 323 Resistance Welding- 3231 Joule Heating- 3232 IRW- 33 Heat Transfer- 331 Modelling the Geometry through the FEM- 332 Heat Transfer Theory- 333 Modelling of Interfaces Between Plies- 334 Non-uniform Heating- 335 Improvement of Heat Transfer in Penetration Area- 34 Modelling Thermal Degradation- 341 Approximation of Thermal Degradation- 342 Thermal Degradation Kinetic Model- 35 Aspects Influencing Heat Transfer in Resistance Welding- 351 Material Properties- 352 Basic Results for Heat Transfer- 353 Effect of Latent Heat- 354 Effect of Rough Contact Surfaces- 355 Non-uniform Heat Generation in Resistance Welding- 36 Simulations of Resistance Welding- 361 Temperature Uniformity in Welding Interface- 362 Processing Windows- 363 Heat Transfer to Laminate- 364 IRW- 3641 In-air HE- 3642 Embedded HE- 37 Concluding Remarks- 38 References- 4 Consolidation Mechanisms- 41 Introduction- 42 Basic Mechanisms for Fusion Bonding- 421 Consolidation Mechanisms- 422 Intimate Contact Model- 423 Autohesion Model- 424 Non-isothermal Bonding Process- 43 Simulations of Consolidation for Resistance Welding- 431 Material Properties- 432 Effect of Surface Roughness on Intimate Contact- 433 Processing Windows- 434 Effect of Consolidation Pressure on Intimate Contact- 435 IRW- 4351 Simulations of Consolidation- 4352 Comparison with Experimental Data- 44 De-consolidation Phenomenon- 45 Concluding Remarks- 46 References- 5 Crystallisation Kinetics- 51 Introduction- 52 Description of Crystallisation Kinetics and Crystal Melting Kinetics Models- 521 Ozawa's Crystallisation Kinetics Model- 522 Velisaris and Seferis' Crystallisation Kinetics Model- 523 The Choe and Lee Crystallisation Kinetics Model- 524 Icenogle's Crystallisation Kinetics Model- 525 The Maffezzoli et al Crystal Melting Kinetics Model- 53 A Transient Crystallinity Model for Resistance Welding- 54 Simulations of the Crystallinity Level- 541 Crystallisation Kinetics- 542 Crystallisation Kinetics Coupled with Crystal Melting Kinetics- 543 Influence of Environmental Temperature- 544 Influence of Latent Heat of Crystallisation and Crystal Melting- 545 Evaluation of the CF-PP/PP Welding Configuration- 55 Concluding Remarks- 56 References- 6 Processing-Microstructure-Property Relationship- 61 Introduction- 62 Experimental Techniques- 621 Laminates- 622 HEs- 623 Resistance Welding- 624 Temperature Measurements- 625 Modelling- 63 Assessing Parent Materials Properties- 64 Heat Generation and Heat Transfer- 641 Resistance of HE- 6411 Measurement of Resistance- 6412 Dependency of Resistance of HE on Temperature- 6413 Influence of Clamping Force on Electrical Contact Efficiency- 642 Determination of Power Density- 643 Efficiency of CF HEs- 644 Temperature Measurements in LS Coupons- 645 Comparison with FEM Predictions- 65 Determination of Processing Windows- 651 Optimised Welding Times- 652 Welding Curves and Thickness Reduction- 653 Welding Pressure and Consolidation Quality- 654 Failure Mechanisms- 655 Processing Window- 656 Fabric HEs- 66 Concluding Remarks- 67 References- 7 Full-scale Fusion Bonding- 71 Introduction- 72 Strategies for Transition to Large-scale Fusion Bonding- 721 Ultrasonic Welding- 722 Induction Welding- 723 Resistance Welding- 73 Large-scale Resistance Welding- 731 Current Leakage to Laminate- 732 Heat Transfer in Welding Stack- 733 Large Width LS Coupons- 734 DCB Coupons- 74 Concluding Remarks- 75 References- 8 Fusion Bonding of TSMC/TPMC Joints- 81 Introduction- 82 Experimental- 83 TP Hybrid Interlayer- 84 Modelling- 85 Characterisation of CF-Epoxy/CF-PEI Joints- 851 Consolidation and Microstructure- 852 Failure Mechanisms- 853 Simulated Results- 854 Optimisation of the Processing Windows- 86 Concluding Remarks- 87 References- 9 Fusion Bonding of Metal/TPMC Joints- 91 Introduction- 92 Experimental- 93 Simulation of Resistance Welding of Aluminium/CF-PEI LS Joints- 931 FEM- 932 Simulation of Temperature and Welding Times- 94 Characterisation of Aluminium/CF-PEI LS Joints- 941 Consolidation and Microstructure- 942 Failure Mechanisms- 943 Annealing of Aluminium Substrates- 944 Optimisation of the Processing Window- 95 Concluding Remarks- 96 References- Appendix A Material Properties for Simulations- Appendix B Parameters for Crystallisation and Crystal Melting Kinetics Models- Appendix C Thermal Degradation Kinetic Model- CI Thermal Degradation Model for CF-epoxy Composite- C2 Thermal Degradation Model for PEI- C3 Thermal Degradation Model for PEEK- C4 References

Solid electrolytic capacitor and its manufacturing method

Abstract: A solid electrolytic capacitor of the present invention has a structure where respective anode sections of capacitor elements are joined to an anode lead frame by resistance welding via a through hole formed in the anode lead frame Current thus collects to the through hole during the welding to break a dielectric oxide film layer to expose aluminum foil, and the molten aluminum collects into the through hole Stable welding work is therefore allowed without splashing the aluminum, and a solid electrolytic capacitor having high welding strength, high reliability, and reduced ESR can be obtained

Laser-assisted friction stir welding

Abstract: Laser-assisted friction stir welding (LAFSW) is a new modification of friction stir welding (FSW), a process developed during the last decade. In FSW, welding heat is produced by friction between the tool and the workpiece. Relatively large forces are needed for this process and, hence, the equipment used in FSW is massive and expensive. LAFSW uses laser energy to heat the workpiece while the main function of the probe is to stir and join the two parts. As a result, LAFS welding can be done with relatively simple and inexpensive systems. This paper describes initial results of the use of LAFS welding to join AZ91D Mg alloy plates and other possible advantages of this method.

Dual beam laser welding

Abstract: In recent years, laser beam welding using two laser beams, or dual-beam laser welding, has become an emerging welding technique. Previous studies demonstrated use of dual-beam laser processing can delay humping onset to higher speeds and slow down cooling rates. In this study, a detailed investigation was performed to quantify the benefits of dual-beam laser processing and to understand the mechanism for improving weld quality. A 6-kW CO 2 laser beam was split into two equal-power beams and the dual beams were located in tandem (one beam follows another) during welding. Experimental results indicated the dual-beam laser could significantly improve weld quality. For steel, surface quality was improved with fewer surface defects such as undercut, surface roughness, spatter, and underfill. Weld hardness and centerline cracking susceptibility were also reduced. In aluminum, quality improvements were in the form of smooth weld surfaces and fewer weld defects such as porosity, surface holes, and undercut. A high-speed camera investigation of welding vapor plumes above a workpiece showed plume height and size changed damatically in conventional single-beam laser welding and the average fluctuation frequency was 1.2 kHz for steel. As the plume fluctuation was associated with keyhole instability, unstable vapor plume indicated the process was unstable and would result in poor welds. The vapor plumes in dual-beam laser welding were found to fluctuate at a certain frequency range, but the plume size changed only slightly during welding. The stabilized process contributed to improved weld quality in dual-beam laser welding.

Electrode sticking during micro-resistance welding of thin metal sheets

Abstract: The electrode sticking mechanism and factors affecting the sticking, including welding current, weld time, electrode tip coating, electrode force and electrode spacing, were studied during micro-resistance welding of very thin nickel-plated steel to nickel sheets in the assembly of a cell-phone battery package. The results indicated that electrode sticking was caused by local metallurgical bonding between the electrode and the nickel-plated steel sheet. The sticking force was proportional to the total area of the local bonds and to the bonding strength between the electrode and sheet. Reducing welding current and weld time, and increasing electrode force and electrode spacing were found to reduce electrode sticking. Welding electrodes with tips coated with TiC metal matrix composite were tried as an alternative to the regular CuCrZr electrode and were found to be more resistant to sticking.

Finite element modelling of resistance spot welding of aluminium with spherical tip electrodes

Abstract: A FEM based simulation model of the resistance spot welding process has been developed. The current simulation accounts for the non-uniform current density distribution in the sheet-electrode geometry and the elastoplastic deformation of the sheet due to electrode force, especially with spherical tip electrodes, since these effects are driven by and contribute to the main heat transfer analysis, which is governed by the internal heat generation within the sheet-electrode geometry as well as along the contact surfaces. The latent heat of transformation during melting or solidification, the variation of sheet/sheet contact resistance with temperature, and temperature dependent thermophysical material properties have been incorporated. The model also calculates the local time-temperature history of the sheet-electrode geometry that can be coupled with appropriate metallurgical reactions to determine metallurgical changes and subsequent mechanical properties in both the fusion zone and the HAZ.

Laser power coupling efficiency in conduction and keyhole welding of austenitic stainless steel

Abstract: Laser welding of thin sheets of AISI 304 stainless steel was carried out with high power CW CO2 laser. The laser power utilized in the welding process was estimated using the experimental results and the dimensionless parameter model for laser welding; and also the energy balance equation model. Variation of laser welding efficiency with welding speed and mode of welding was studied. Welding efficiency was high for high-speed conduction welding of thin sheets and also in keyhole welding process at high laser powers. Effect of pre-oxidization of the surface and powder as filler material on laser power coupling is also reported. The paper also discusses effect of microstructure on the cracking susceptibility of laser welds.

Welding wire feeder

Abstract: A push-pull welding wire feeder includes plural wire feeding units provided in a wire feeding passage extending from a welding wire magazine, in which a roll of welding wire is accommodated, via a wire guide tube to a welding torch At least one of the wire feeding units includes a torque limiter provided in a driving transmission system thereof for transmitting a driving force from a driving source to the welding wire Accordingly, the welding wire feeder can steadily convey the welding wire even at acceleration or deceleration while allowing the welding wire to be bent, thus contributing to favorable result of its welding operation

Robust Control of Pulsed Gas Metal Arc Welding

Abstract: A system is developed to control the pulsed gas metal arc welding process. To achieve controlled detachment of the droplet, the welding current is switched from a peak level to a background level to induce droplet oscillation. When the droplet moves downwards, the current is switched back to peak level. The combination of downward momentum of the oscillating droplet and increased electromagnetic force guarantees detachment of the droplet. Instead of adjusting duration of the background current, the waveform of the current is adjusted to control the melting rate of the electrode wire without having to change the transfer frequency. It is found that the dynamic model of the process depends on welding operational parameters, which vary with applications, and therefore it is unrealistic for operators to provide welding machines these parameters as inputs. Hence, welding operational parameters are considered as unfixed and their ranges are used to quantify the resultant uncertainty in the dynamic model. As a result, the process is controlled using a single algorithm at different operational parameters. Experiments verified the effectiveness of the system in overcoming two common variations in welding operational parameters, wire speed and contact tube-to-work distance.

Welding Characteristics of Aluminum and Copper Plate Specimens Welded by a 19 kHz Complex Vibration Ultrasonic Seam Welding System

Abstract: The welding characteristics of aluminum and copper plate specimens welded using a 19 kHz ultrasonic welding system with a complex-vibration welding tip were studied. The welding tip part vibrates in an elliptical or circular locus. The seam welding system uses a rotating circular disk welding tip and a shifting stage for continuous welding of the metal sheets. Using the complex-vibration system, metal plates of various thicknesses can be welded continuously at multiple positions with large and uniform welded areas and large weld strengths independently of the welding position and direction. The required complex-vibration amplitude is less than one-half of that of a conventional linear-vibration system. Aluminum-aluminum, aluminum-copper and copper-copper plate specimens were welded with weld strengths almost equal to the specimen strength.

Magnetically Impelled Arc Butt Welding of Hollow and Solid Parts

Abstract: Magnetically Impelled Arc Butt (MIAB) welding is mainly used in the automotive industry for butt welding of tubes and tubular parts 8–100mm in diameter and 0.8–6mm wall thickness. To extend the range of MIAB welding applications research work was conducted on different hollow and solid parts, special attention being given to welding of parts, the cross section of which is commensurable with of the active spot diameter of the rotating arc.

Mechanically assisted droplet transfer process in gas metal arc welding

Abstract: Gas metal arc welding has been generally accepted as the preferred joining technique due to its advantages in high production and automated welding applications. Separate control of arc energy and arc force is an essential way to improve the welding quality and to obtain the projected metal transfer mode. One of the most eVective methods for obtaining separate control is to exert an additional force on the metal transfer process. In this paper, the droplet transfer process with additional mechanical force is studied. The welding system is composed of an oscillating wire feeder. The images of molten metal droplets are captured by a high-speed digital camera, and both the macroscopic appearance and the cross-sectional pro®les of the weld beads are analysed. It is shown that the droplet transfer process can be signi®cantly improved by wire electrode oscillation, and a projected spray transfer mode can be established at much lower currents. By increasing the oscillation frequency, the droplet transfer rate increases while the droplet size decreases. In addition, the improvement in the droplet transfer process with wire oscillation leads to an enhancement of the surface quality and a modi®cation of the geometry of the weld beads that could be of importance for overlay cladding and rapid prototyping based on deposition by welding.

低入熱摩擦圧接における摩擦時間, 摩擦トルクと継手特性の関係 :摩擦圧接の接合メカニズムに関する研究 (第3報)

Abstract: In the previous reports 1 and 2, the authors have clarified the joining mechanism in the first phase of friction stage during friction welding process. The present paper describes the relationship between the friction time, friction torque, and joint properties of friction welding for a low heat input friction welding method. The materials joined were mild steels (same materials), and a brake type friction welding machine was used for joining. In actual experiment, i.e., the low heat input friction welding method (LHI method), the electromagnetic clutch was used in order to exclude braking deformation at rotation stopping. The following are concluded. (1) The joints obtained only in the first stage (up to initial peak torque) had 100% joint efficiency and 90 degrees bend ductility with no crack. It was determined that friction welded joints with 100% joint efficiency and good bend ductility could be obtained by using only the friction stage up to initial peak torque and without the need for the forging (upsetting) stage. (2) The fracture occurred at the substrates (not at the welded interface) in welded joints when friction torque was close to initial peak torque. It was clarified that those joints has less width of heat affected zone and less width of hardening. (3) It was clarified that the friction welded joints without using the forging stage (the friction welded joints by using the LHI method) have same mechanical properties as those welded by the conventional friction welding process including that stage. The LHI method has more advantages, i.e., less burn-off and less burr.

Process Modeling and Optimization of Resistance Welding for Thermoplastic Composites

Abstract: Resistance welding is a suitable technique for joining thermoplastic composites. Like other fusion bonding processes, it involves heating, melting and cooling steps. Productivity depends on the time that passes during these steps. This is the first study that tries to increase the productivity of the process in a systematic way. The objective of the present study is to determine the optimum set of process parameters to minimize the processing time. In order to ensure that the resulting joint satisfied the requirements of quality, the relationship between process variables and quality of the welded joint was established through process modeling. First, a one-dimensional transient heat transfer analysis was carried out using a finite difference method to find the temperature profiles across the thickness of the welding stack. Then, the heat transfer analysis was coupled with a degradation kinetics model in order to determine whether the resulting part has undergone excessive thermal degradation, or not. Fin...

Suppressing Cracking in Resistance Welding AA5754 by Mechanical Means

Abstract: In this paper mechanical aspects of cracking during single- and multi-spot welding of AA5754 was investigated by both experimental and analytical approaches. The impact of mechanical loading on crack initiation and propagation was studied with the consideration of various process parameters including the loading imposed by electrodes, the formation of liquid nugget, and constraining factors during and after welding. Tensile properties of AA5754 and their dependence on the temperature were tested at room and up to solidus temperatures, in order to provide a reference of cracking stress. Thermalmechanical analysis was conducted based on the temperature field around the nugget and the state of stress encountered during welding. This analysis revealed that tensile stress might build up in the vicinity of the nugget during cooling, as explained in the experimental observation. General guidelines for suppressing cracking were proposed, i.e., to provide sufficient constraint around the weld spot during and after welding. @DOI: 10.1115/1.1418693#

Welding method, welding device, welded joint, and welded structure

Abstract: A welding method for butt-welding a first base material (1) and a second base material (2) in order to make it possible to stably and efficiently form a fillet weld-shaped bead also on the back side of a groove by arc welding from the groove side without providing a bead on the back side of the groove in advance, comprising the steps of abutting, against the root face (1a) of a first member (1) formed with a root face (1a) and a one-side grooved surface (1b), the flat surface (2a) of the second base material (2), facing a welding wire (6) with a groove formed by abutment between the first and second base materials (1, 2), melting the abutted portions, etc of the first and second base materials (1, 2) by the arc of the welding wire (6), extruding the melt formed by the welding of the abutted portions, etc to the back side of the groove so as to form a fillet weld-shaped bead (B4)

Resistance welding device and control method

Abstract: The invention relates to a method and a device for controlling and particularly for adjusting a resistance welding electrode holder (2). The robot-controlled (3) relative position for welding between the electrode holder (2) and the workpiece (5) is determined and adjusted by means of an adjustment method. In a relative search movement, a contact or a gap between one electrode (8) and the workpiece (5) is searched and determined. The corresponding data concerning the position or power measurements is simultaneously recorded and compared in the robot control mechanism (4) and the correct relative position is then determined from the comparison data and initiated. The contact between the electrode (8) and the workpiece (5) is preferably determined by means of an electrical contact detection system (31).

Process for welding of thermoplastic resins

Abstract: Weld bead of excellent surface features with high welding strength can be obtained without development of significant shrinkage and thermal damages.