scispace - formally typeset
Search or ask a question

Showing papers on "Electric resistance welding published in 2015"


Journal ArticleDOI
TL;DR: In this article, a comparative evaluation of mechanical properties and microstructural features of shielded metal arc, gas metal arc and friction stir welded (FSW) naval grade HSLA steel joints was carried out.

158 citations


Journal ArticleDOI
TL;DR: In this article, the weldability criteria which should be met to achieve good welds were calculated for aluminum-copper joints for different morphologies for welding interface (straight, wavy and melted layer) were obtained with changing welding parameters.

144 citations


Journal ArticleDOI
TL;DR: In this article, the authors present an overview of the key factors related to the formation of defects in welding methods commonly used with aluminium alloys, such as friction-stir welding, laser beam welding and arc welding.
Abstract: Transportation industries are obliged to address concerns arising from greater emphasis on energy saving and ecologically sustainable products. Engineers, therefore, have a responsibility to deliver innovative solutions that will support environmental preservation and yet meet industries’ requirements for greater productivity and minimised operational costs. Aluminium alloys have successfully contributed to meeting the rising demand for lightweight structures. Notable developments in aluminium welding techniques have resolved many welding related problems, although some issues remain to be addressed. The present study attempts to give an overview of the key factors related to the formation of defects in welding methods commonly used with aluminium alloys. First, a concise overview of defects found in friction-stir welding, laser beam welding and arc welding of aluminium alloys is presented. The review is used as a basis for analysis of the relationship between friction-stir welding process parameters and weld defects. Next, the formation and prevention of the main weld defects in laser beam welding, such as porosity and hot cracking, are discussed. Finally, metallurgical aspects influencing weld metal microstructure and contributing to defects are tabulated, as are defect prevention methods, for the most common flaws in arc welding of aluminium alloys.

129 citations


Journal ArticleDOI
TL;DR: In this article, a comprehensive overview on joining battery cells by resistance spot, ultrasonic and laser beam welding is presented, and a quantitative analysis on welded test samples reveals the ultimate tensile strength and heat input into a battery cell.
Abstract: In large battery assemblies, which are integrated, for example, in electric vehicles or stationary storage systems, up to several thousand single battery cells are connected together. Every single cell connection influences the functionality and efficiency of the whole battery system. Resistance spot, ultrasonic or laser beam welding are mostly used for connecting battery cells in the production of large battery assemblies. Each of these welding techniques has its own characteristics depending on the material properties and contact geometry. Cell casing and terminal dimensions may constrain possible contact geometries. For example, pouch cells provide detached tabs, whereas cells with hard casing provide a certain area of the casing for electrical connection. Consequently, it is a challenging task to find the most suitable welding technique and welding parameters for each individual battery assembly. This paper presents a comprehensive overview on joining battery cells by resistance spot, ultrasonic and laser beam welding. The specific features, advantages and dependencies of each welding technique for connecting cells are discussed. In addition, a quantitative analysis on welded test samples reveals the ultimate tensile strength and heat input into a battery cell. A novel measuring and calculation method was designed and applied to assess the electrical contact resistance itself. The electrical contact resistance occurs as a result of the joint and not in the bulk material. Therefore, it is a criterion which may be transferred to any size of joint partners.

128 citations


Journal ArticleDOI
TL;DR: In this paper, a mathematical model was developed to predict the corrosion resistance of friction stir welded AA2219 aluminium alloy by incorporating FSW process parameters, such as tool pin profile, rotational speed, welding speed and axial force.

121 citations


Journal ArticleDOI
TL;DR: In this paper, a keyhole gas tungsten arc welding (K-TIG) was used to weld AISI 316L stainless steel of mid-thickness.

112 citations


Journal ArticleDOI
TL;DR: In this article, a 10kW fiber laser welding system with ER4043 filler metal was used to join aluminum alloy to steel by butt joints when zinc layer was hot-dip galvanized at the steel's groove face in advance.

105 citations


Journal ArticleDOI
TL;DR: In this article, an electrically assisted friction stir welding (FSW) system has been developed, which enables a local electrical current field moving with the FSW tool without requiring the tool to be one of the electrodes.

102 citations


Journal ArticleDOI
TL;DR: In this paper, a criterion for solidification cracking in laser welding of 2024 aluminum alloy was proposed. But the authors did not consider non-steady conditions and interpreted with respect to the loci of relevant isotherms and the length of the vulnerable zone in the melt pool.

102 citations


Journal ArticleDOI
TL;DR: In this article, a very fast joining technique for thermoplastic composites is described, which does not require the use of foreign materials at the welding interface for either carbon or glass.
Abstract: Ultrasonic welding is a very fast joining technique well suited for thermoplastic composites, which does not require the use of foreign materials at the welding interface for either carbon or glass...

98 citations


Journal ArticleDOI
TL;DR: In this paper, a mathematical model was developed to analyze the effects of superimposed ultrasonic vibration on heat generation, temperature distribution and material flow in friction stir welding process, and validated by a comparison of the calculated thermal cycles and thermo-mechanically affected zone boundaries with the experimentally measured ones.

Journal ArticleDOI
Hong Ma1, Guoliang Qin1, Peihao Geng1, Fei Li1, Banglong Fu1, Xiangmeng Meng1 
TL;DR: In this article, the microstructure variation and mechanical properties of carbon steel and 304 stainless steel are studied in detail, and the weld interface can be clearly identified in central zone, while the two metals interlock with each other by the mechanical mixing in peripheral zone.

Journal ArticleDOI
TL;DR: In this paper, the authors quantitatively compare the energy consumption associated with the creation of full-penetration welds in aluminum 6061-T6 workpieces by FSW and gas metal arc welding (GMAW) processes.
Abstract: One of the advantages of friction stir welding (FSW) is reduced energy consumption as compared to arc welding processes. This advantage has been predicted and qualitatively established. However, a quantitative analysis based on energy measurements during the processes and how to equitably compare them is missing. The objective of this work is to quantitatively compare the energy consumption associated with the creation of full-penetration welds in aluminum 6061-T6 workpieces by FSW and gas metal arc welding (GMAW) processes. The workpiece thicknesses for the two processes (5-mm-thick for FSW and 7.1-mm-thick for GMAW) are chosen such that the maximum tensile force sustained by the joints during tensile testing is similar. This accounts for material saving due to the higher ultimate tensile strength resulting from FSW. The energy consumed for any pre-processes, the welding processes, and post-processes was measured. Finally, a life cycle assessment (LCA) approach was used to determine and compare the environmental impact of FSW and GMAW. For the welding parameters used in this study joining by FSW consumes 42% less energy as compared to GMAW and utilizes approximately 10% less material for the design criteria of similar maximum tensile force. This leads to approximately 31% less greenhouse gas emissions for FSW as compared to GMAW. Both, the lower energy consumption during FSW, and involved pre and post processes contributed in the overall energy reduction.

Journal ArticleDOI
TL;DR: In this paper, the effect of arc and laser powers on the quality of the arc assisted fiber laser welding of an Al-Mg alloy in the butt configuration was analyzed and the power distribution that stabilized the welding process and minimized the weld porosity was defined.
Abstract: This paper treats of the analysis of the effect of arc and laser powers on the quality of the arc assisted fiber laser welding of an Al–Mg alloy in the butt configuration. Grain size, weld geometry defects, porosity, and magnesium loss were measured. Magnesium content of the fused zone decreased as the laser power increased while the porosity increased with laser power. Microhardness profiles and tensile properties were explained on the basis of the joint microstructure and defects and related to the power distribution. The porosity level and Mg content in the fused zone affected both tensile strength and ductility. The power distribution that stabilized the welding process and minimize the weld porosity was defined.

Journal ArticleDOI
TL;DR: In this paper, the influence of ultrasonic vibration on the formation, microstructure and mechanical properties of butt welded 2024Al-T4 joints was investigated, and the underlying mechanism of UVeFSW by experimental methods.
Abstract: Ultrasonic vibration enhanced friction stir welding (UVeFSW) is a new variant of friction stir welding (FSW) in which a sonotrode transmits ultrasonic energy directly into the localised area of the workpiece near and ahead of the rotating tool. This study investigated the influence of ultrasonic vibration on the formation, microstructure and mechanical properties of butt welded 2024Al-T4 joints, and attempted to unveil the underlying mechanism of UVeFSW by experimental methods. Morphology inspection, X-ray detection and metallographic inspection of the welds revealed that ultrasonic vibration can improve the weld formation at higher welding speeds. The stir zone in the UVeFSW broadened, while the grains in the heat affected zone had no obvious growth contrary to that in the base metal. Results of the mechanical tests indicated that the tensile strength and elongation of joints, and the microhardness value in the stir zone increased at the same welding parameters.

Journal ArticleDOI
TL;DR: In this article, a finite element method (FEM) incorporating the cast microstructure and alloy chemical composition was used to calculate the welding stresses and predict crack initiation, and a pre-welding homogenization heat treatment, lower welding heat input, and post welding crater grinding of each individual welding seam can decrease its hot cracking susceptibility.

Journal ArticleDOI
TL;DR: In this article, the authors developed a simulation model for the Al-steel resistance spot welding process, which directly couples the thermal, electrical, metallurgical and mechanical fields and solves the equations simultaneously.

Journal ArticleDOI
TL;DR: In this article, a hybrid friction-stir welding process, i-FSW, is presented for the joining of thermoplastics, where the friction tool during welding is heated by induction and the temperature is precisely maintained though feedback control.

Journal ArticleDOI
TL;DR: In this paper, the distinction and characterization of aluminum to steel joints made by friction stir welding is investigated, and an attempt to address sub-techniques into three categories i.e., diffusion, plunging and annealing is made.
Abstract: Friction stir welding exploits its solid state process behaviour to join aluminum to steel, which differs in thermal and mechanical properties, and where combination of these metallic alloys by fusion welding prompts a deleterious reaction as a result of the melting and resolidification phases. This review investigates the distinction and characterization of aluminum to steel joints made by this welding method. An attempt to address sub-techniques into three categories i.e., diffusion, plunging, and annealing, is made. Steel fragments spattered at the weld zone, weld defects, sharp difference in grain size distribution, and the formed phases of the intermetallic layer and its thickness are discussed, these factors and the process welding parameters are significantly influenced the joint’s strength of this welding method.

Journal ArticleDOI
TL;DR: In this paper, a new type of shielding arrangement is experimented for joining commercially pure titanium sheets with variations in the gas tungsten arc welding (GTAW) process parameters namely the welding current and travel speed.
Abstract: Gas Tungsten Arc Welding (GTAW) is a commonly used welding process for welding Titanium materials. Welding of titanium and its alloys poses several intricacies to the designer as they are prone to oxidation phenomenon. To overcome this contamination, a relatively new type of shielding arrangement is experimented. The proposed design and arrangement have been employed for joining commercially pure titanium sheets with variations in the GTAW process parameters namely the welding current and travel speed. Bead on plate (BoP) trials were conducted on thin sheets of 2 mm thickness by varying the process parameters. Subsequently, the macro structure images were captured. Based on these results, the process parameters are chosen for carrying out full penetration butt joints on 1.6 mm and 2 mm thick titanium sheets. The influences of these parameters of GTAW on the microstructure, mechanical properties and surface morphology at the fractured locations of the welded joints are examined. The microstructural properties of base metal, heat affected zone and fusion zone are analyzed through optical microscopy. The welded joints showed an ultimate tensile strength of about 383 MPa with 15.7% elongation. The hardness value at fusion zone and base metal are typically observed to be 191 and 153 HV-0.5, respectively. X-ray diffraction study is conducted to examine the chemical composition in the parent metal and fusion zone of the weld. Fractured surface is examined using Scanning Electron Microscopy which revealed dimple kind of rupture present at the fractured surfaces owing to insufficient or excessive heat with slight impurities that prevents the accomplishment of stronger micro-level weld integrity.

Journal ArticleDOI
TL;DR: In this article, microstructural characterization was carried out to identify various zones on either side of the fusion boundaries of SUS 304H and Inconel 617 (IN 617) filler material and the procedure was successfully established along with optimized welding parameters.
Abstract: At moderately high temperature sections of Advanced Ultra Super Critical (AUSC) boilers, welding of superalloys to austenitic steels is inevitable owing to economic aspects of boiler. Welding of SUS 304H and Inconel 617 (IN 617) was attempted using IN 617 filler material employing conventional Gas Tungsten Arc Welding (GTAW) process and the procedure was successfully established along with optimized welding parameters. Microstructural characterization was carried out to identify various zones on either side of the fusion boundaries. Unmixed Zone and Heat Affected Zone (HAZ) were observed towards SUS 304H fusion boundary while no distinct HAZ was observed towards IN 617 fusion boundary. Micro-hardness profiling indicated decrease in hardness at the HAZ towards SUS 304H fusion boundary. Mechanical properties evaluation at both ambient and elevated temperatures was carried out and data obtained was compared with those of base metals. The tensile strength of the cross weld specimens at high temperatures were observed to be marginally lower than that of IN 617 but significantly more than that of SUS 304H, hence, tolerable. Stress-rupture properties of the cross-weld specimens as tested in this study were found to be intermediate to the base metals’ data, thus, suitable for AUSC power plants' boiler applications. Hence, this work gives an insight into welding procedure establishment, microstructural development, variation of mechanical properties at elevated temperatures and stress-rupture properties of the dissimilar metal welds at elevated temperatures.

Journal ArticleDOI
TL;DR: In this article, full penetration welding of 2mm thick Ti6Al4V plates in butt configuration was performed by adopting a high brightness Yb fiber laser, and the influence of different welding conditions on the bead morphology, metallurgy and mechanical properties was discussed in detail.

Journal ArticleDOI
TL;DR: In this paper, the microstructures of the ultrasonic welds between three layers of lithium-ion battery tabs (either Al or Cu) and bus bars were studied, and the weld formation mechanism and failure modes were investigated.

Journal ArticleDOI
Farid Haddadi1
TL;DR: In this paper, the interfacial reaction between aluminum 6111-T4 and DC04 uncoated steel has been investigated as a function of welding time, showing that deformation induced vacancies during the thermomechanical welding process accelerates formation of intermetallic layer at the interface.

Journal ArticleDOI
TL;DR: In this paper, Shenyang National Laboratory for Materials Science (NLLS) proposed a method to improve the performance of the Li-FeFei-Fei lattice.

Journal ArticleDOI
TL;DR: In this paper, the microstructural analysis indicates that in the weld nugget the grains of the upper layer are smaller than those of the lower layer, which should be attributed to the larger extent of heat dissipation through the top shoulder.

Journal ArticleDOI
TL;DR: In this article, the effect of welding processes on the microstructure, residual stresses and distortion in 16mm thick 316LN stainless steel weld joints made by TIG and A-TIG (activated flux tungsten inert gas) welding processes involving different joint configurations have been studied.

Journal ArticleDOI
TL;DR: In this paper, a prototypal setup is developed to monitor the evolution of main forces and tool temperature during the joining phases, and an Artificial Neural Network has been developed in order to predict the mechanical behavior of the welded joints.

Journal ArticleDOI
TL;DR: In this paper, the friction welding characteristics between Ti-6Al-4V and SS304L into which pure oxygen free copper (OFC) was introduced as interlayer were investigated.

Journal ArticleDOI
TL;DR: In this paper, the effect of coating density of activating flux on the weld pool shape and oxygen content in the weld after the welding process was studied systematically, and the maximum depth/width ratio of stainless steel activated TIG weld was obtained when the coating density was 2.6, 1.3, 2, and 7.8 µm2 for SiO2, TiO2 and Cr2O3, respectively.
Abstract: The use of activating flux in TIG welding process is one of the most notable techniques which are developed recently. This technique, known as A-TIG welding, increases the penetration depth and improves the productivity of the TIG welding. In the present study, four oxide fluxes (SiO2, TiO2, Cr2O3, and CaO) were used to investigate the effect of activating flux on the depth/width ratio and mechanical property of 316L austenitic stainless steel. The effect of coating density of activating flux on the weld pool shape and oxygen content in the weld after the welding process was studied systematically. Experimental results indicated that the maximum depth/width ratio of stainless steel activated TIG weld was obtained when the coating density was 2.6, 1.3, 2, and 7.8 mg/cm2 for SiO2, TiO2, Cr2O3, and CaO, respectively. The certain range of oxygen content dissolved in the weld, led to a significant increase in the penetration capability of TIG welds. TIG welding with active fluxes can increase the delta-ferrite content and improves the mechanical strength of the welded joint.