Showing papers on "Electric resistance welding published in 2016"
TL;DR: In this paper, approximated examples of the use of the electron beam are given by the welding, rapid prototyping, texturing surface, cladding with wire and powder as well as alloying.
257 citations
TL;DR: In this paper, the current state of understanding and development of RFW and LFW is presented, focusing on the process parameters, joint microstructure, residual stresses, mechanical properties and their relationships.
Abstract: Friction welding (FW) is a high quality, nominally solid-state joining process, which produces welds of high structural integrity. Rotary friction welding (RFW) is the most commonly used form of FW, while linear friction welding (LFW) is a relatively new method being used mainly for the production of integrally bladed disc (blisk) assemblies in the aircraft engine industry. Numerous similar and dissimilar joints of structural metallic materials have been welded with RFW and LFW. In this review, the current state of understanding and development of RFW and LFW is presented. Particular emphasis is placed on the process parameters, joint microstructure, residual stresses, mechanical properties and their relationships. Finally, opportunities for further research and development of the RFW and LFW processes are identified.
220 citations
TL;DR: Different forms of laser beam welding including single beam laser welding, dual-beam laser welding and laser arc hybrid fusion-brazing welding are reviewed in this paper, where the main problems are how to control the thickness of the intermetallic compound layer and reduce or avoid the generation of pores, cracks, and thermal stresses which severely limit the mechanical properties of welded joints.
Abstract: Joining aluminum to steel can lighten the weight of components in the automobile and other industries, which can reduce fuel consumption and harmful gas emissions to protect the environment. However, the differences of thermal, physical, and chemical properties between aluminum and steel bring a series of problems in laser welding. The main problems are how to control the thickness of the intermetallic compound layer and reduce or avoid the generation of pores, cracks, and thermal stresses which severely limit the mechanical properties of welded joints. Laser fusion-brazing technology utilizes the precise control of heat input with or without filler to partially melt the low melting temperature aluminum base material and promote wetting on the high melting temperature steel base material in order to achieve sound metallurgical by combining the advantages of fusion welding and brazing. Different forms of laser beam welding including single beam laser welding, dual-beam laser welding, and laser arc hybrid fusion-brazing welding are reviewed.
114 citations
TL;DR: In this article, an attempt has been made to perform friction welding of dissimilar plastic based materials by controlling the melt flow index (MFI) after reinforcement with metal powders.
Abstract: Friction welding is one of the established processes for joining of similar as well as dissimilar polymer/plastics and metals. In past 20 years numbers of application in different areas using this process have been highlighted, but very limited contributions have been reported on properties of friction welded joints of dissimilar polymer/plastic materials after reinforcement with metal powder. In the present work an attempt has been made to perform friction welding of dissimilar plastic based materials by controlling the melt flow index (MFI) after reinforcement with metal powders. The present studies of friction welding for dissimilar plastic were performed on Lathe by considering three input parameters (namely: rotational speed, feed rate, and time taken to perform welding). Investigations were made to check the influence of process parameters on mechanical and metallurgical properties (like: tensile strength, Shore D hardness and porosity at joint). The process parameters were optimized using Minitab software based on Taguchi L9 orthogonal array and results are supported by photomicrographs.
104 citations
TL;DR: In this article, sound Al Zn-steel "sandwich" joints were achieved with the tool pin inserted into zinc foil, vast zinc was stirred into aluminum fabricating AlZn mixing layer structure in the upper part of aluminum side and no intermetallic compound interlayer was discovered at the interface.
100 citations
TL;DR: In this article, the authors investigated the effect of welding parameters such as torch arrangement, distance between heat sources and shielding gas composition on the quality of laser-arc hybrid welds.
94 citations
TL;DR: The welds with weld energies of more than 1.05 kJ fracture in the base metal and were severely deformed by the ultrasonic vibration, and recrystallization occurred around the weld interface owing to the shear deformation and heating during ultrasonic welding as discussed by the authors.
87 citations
TL;DR: In this paper, the effects of zinc layer on microstructure and mechanical behavior of resistance spot welds of aluminum to galvanized (GS-Al joint) and low carbon steel (PS-Al Joint) were explored.
87 citations
TL;DR: In this article, the microstructure, hardness, lap shear strength and fracture energy of AA2139-TiAl6V4 spot joints produced by ultrasonic welding were investigated and related to the weld thermal cycle.
82 citations
TL;DR: In this paper, a hybrid laser-arc welding technique was developed for one-pass welding of 25mm thick steel plates, and the parts to be welded were assembled into a butt joint configuration with a square groove and 2.5mm air gap.
75 citations
TL;DR: In this paper, the microstructure and chemical composition of the explosively joined samples were investigated and the results demonstrated that explosive welding is an effective way to produce Ti/Al laminates.
TL;DR: In this article, the effect of pulse profiles used in laser welding was studied by investigating weld appearance, weld geometry, microstructure, hardness variation, joint strength and failure mode of welds.
TL;DR: In this paper, the weld appearance, microstructure, and fracture behavior of the joints made by the single/dual-beam laser welding were investigated comparatively, and the results showed that dual-beam welding had better process stability and made better weld appearance and bigger effective joining width which enhanced tensile capacity.
Abstract: Dissimilar metal welding of Q235 low carbon steel and 5052 aluminum alloy was carried out by a single/dual-beam laser in a steel-on-aluminum overlap configuration with a copper interlayer. The weld appearance, microstructure, and fracture behavior of the joints made by the single/dual-beam laser welding were investigated comparatively. The results showed that dual-beam laser welding, compared with single-beam laser welding, had better process stability which made better weld appearance and bigger effective joining width which enhanced tensile capacity. With a copper interlayer, a contact reaction zone appeared between the copper interlayer and aluminum matrix, which enlarged effective joining zone. The microstructures of the welding joint welded by a single/dual-beam laser were composed of the ligulate fusion zone with Fe-Al interface and the contact reaction brazing zone with Al-Cu interface. The Fe-Al interface mainly consisted of α-Al and Al2Cu eutectic structure, FeAl, FeAl2, and a certain amount of Al-Cu intermetallics, Fe2Al5 and FeAl3. The Al-Cu interface mainly consisted of eutectic phase Al2Cu and metastable phase of Al-Cu intermetallics. The tensile property was enhanced by a dual-beam laser, and the addition of the copper-foil interlayer might improve the metallurgical reaction of interfacial reaction region and promote the load-carrying ability of weld joint. An ideal joint with fewer defects could be obtained when the welding speed is 0.9–1.25 m/min of dual-beam laser welding and 1.5–1.75 m/min of single-beam laser welding.
TL;DR: In this paper, 6013 aluminum alloy and AZ31 magnesium alloy were joined by friction stir welding (FSW) in immersed (underwater) and conventional (in air) conditions.
Abstract: In this study, 6013 aluminum alloy and AZ31 magnesium alloy were joined by friction stir welding (FSW) in immersed (underwater) and conventional (in air) conditions. The effect of the immersion method on the microstructure and mechanical properties of the joint was investigated, aiming to reduce the deterioration of the mechanical properties of the joint. The results indicated that with rotation speed of 1,200 rpm and welding speed of 80 mm/min, the water cooling welding resulted in better joint and improved the joint strength to 152 MPa, but the strength of welded joint in air was only about 131 MPa. In air condition, the welding zone was stirred stronger, and the microhardness value was higher than that in water condition. Both the joints welded in air and underwater conditions failed through brittle fracture.
TL;DR: In this article, an improved representation of both electrical contact resistance and thermal contact resistance (TCR) in Al to zinc-coated steel RSW process is presented, which can be used to guide future welding schedule development or electrode geometry design for the RSW of Al to steel.
TL;DR: In this article, the microstructure, mechanical properties, thermal properties, and electric properties of 4mm thick T2 copper joints between double-sided MIG (DMIG) welding and single-pass laser-MIG hybrid (HYBRID) welding were compared.
TL;DR: In this paper, a three-dimensional weak coupling modeling method of the arc and metal transport is developed to simulate the arc, molten pool dynamic and droplet impingement in arc welding based additive manufacturing.
TL;DR: In this article, the overlapping welding in a keyhole mode with a magnetic field perpendicular to the welding direction was carried out between stainless steel 301 and aluminum alloy 5754 in this study, which indicated that the application of the magnetic field can modify the weld bead appearance and microstructure of the weld by the Lorenz force and thermoelectric magnetic force induced in the molten pool.
TL;DR: In this article, a review on resistance spot welding of magnesium alloys is presented, with emphasis on the relationship between microstructure, properties, and performance, under quasi-static and dynamic loading conditions.
Abstract: This paper presents a review on resistance spot welding of magnesium alloys, with emphasis on the relationship between microstructure, properties, and performance, under quasi-static and dynamic loading conditions. It also compares the resistance spot welding of magnesium-to-aluminum alloys and the various techniques used to suppress the formation of brittle intermetallic compounds. Resistance spot welding of magnesium-to-steel, weld bonding, the effects of process parameters on joint quality, and the main metallurgical defects in resistance spot welding of magnesium alloys are also deliberated. Studies have shown that the pre-existence of coarse second phase particles in the base metal, the addition of particles, such as titanium powder, and welding under the influence of electromagnetic stirring effect can promote columnar-to-equiaxed transition, microstructure refinement, and improvement in mechanical properties of magnesium alloys resistance spot welds. For magnesium-to-aluminum alloys spot welds, the use of interlayers, such as pure nickel, gold-coated nickel foil, and zinc-coated steel, was found to suppress the formation of brittle intermetallic compounds and thus significantly improve the joint strength.
TL;DR: In this article, friction stir welding of dissimilar heat treatable aluminium alloys 7020-T651 and 6060-T6 has been studied based on results obtained from temperatures and efforts measurements in a range of advance speed from 300 to 1100 mm and rotation speed from 1000 to 2000 rev min(-1).
TL;DR: In this paper, the effect of welding current and welding speed on heat input, depth of penetration, weld pool width, reinforcement height, dilution, weld bead contact angle parameters during cold metal transfer (CMT) process is investigated.
TL;DR: MIG-TIG double-sided arc welding (DSAW)-brazing process was firstly conducted to join aluminum alloy and stainless steel using Al-Si filler metal and Nocolok flux as discussed by the authors.
TL;DR: In this paper, the acoustic patterns of resistance spot welding in a servo-based electrode actuation system were analyzed using time and frequency domain representations, and the welding processes can be significantly put into classes for their behaviour (weld formation) based on acoustic emissions.
Abstract: Acoustic emission reveals certain characteristic in resistance spot welding process as it exists due to the variation of electromagnetic ties between atomic bounds. So, the objective of this study is to analyse the acoustic patterns of resistance spot welding in a servo-based electrode actuation system. Time and frequency domains’ representations are interchangeably applied to analyse such matters as those behaviours are captured via electronics means. More than one type of weldable materials (carbon steels and stainless steels) is purposely used to analyse the dissimilarity conditions as well as the individual material’s welding processes. The interpreted waveform shows that the welding processes can be significantly put into classes for their behaviour (weld formation) based on acoustic emissions. A best weld formation will have perfect acoustic pattern, while a better one will have more than one main lobe in frequency domain. Moreover, a dissimilar weld formation will have inter-transient spike waveform, while an expulsion welding process will have a rapid drop of signal in acoustic pattern. All these observations have been revealing dissimilar characteristic of welding processes to certain degrees when the fusion process is concerned in resistance spot welding.
TL;DR: In this paper, a study of the fatigue life was carried out on specimens welded with the above mentioned optimized process parameters, and the results showed that for a relatively low load, corresponding to 10% of the maximum supported by the joint, the number of cycles surpasses 1.
TL;DR: In this paper, a review on the various techniques and processes of applying vibration to the welding system and their effects on microstructure, mechanical properties and residual stress of welds, and the directions for future research are presented.
Abstract: Vibration assisted welding (VAW) has emerged as a successful replacement for heat treatments and post-weld vibration treatments of arc welds to reduce residual stresses and distortions and thus to improve its mechanical properties. This review paper tries to create a knowledge platform for such a next generation research by consolidating the findings, merits, demerits and shortfalls identified hitherto in the field of VAW. This paper presents a review on the various techniques and processes of applying vibration to the welding system and their effects on microstructure, mechanical properties and residual stress of welds, and the directions for future research are presented. Vibration of workpiece during welding, oscillation of weld pool, oscillation of molten droplet, oscillation of welding arc and vibration of welding electrode were identified from the literature as the possible ways of imparting vibration. The advancement in the direction of computational work is also observed.
TL;DR: In this paper, a novel resistance element welding technology was applied to join 6061 Al alloy and uncoated 22MnMoB boron steel, and a technological hole was drilled in the Al sheet into which a Q235 steel rivet was inserted, and resistance spot welding was carried out at the rivet.
Abstract: A novel resistance element welding technology was applied to join 6061 Al alloy and uncoated 22MnMoB boron steel. To conduct the resistance element welding process, a technological hole was drilled in the Al sheet into which a Q235 steel rivet was inserted. Resistance spot welding was carried out at the rivet. The mechanical properties, fracture morphology, nugget formation process, dynamic resistance, microstructure, and hardness distribution of the resistance element welding were investigated. Traditional resistance spot weld joints were also prepared for comparison. Resistance spot welding could barely join Al 6061 and boron steel, and had a maximum tensile shear force of less than 1000 N. Novel resistance element welding could join the metals reliably with a maximum tensile shear force of over 7000 N and a relatively high toughness. Nugget formed at the interface of rivet and steel acted as loading position, and IMC interlayer connected rivet and aluminum.
TL;DR: In this article, thin sheets of Ti-6Al-4V were full penetration welded using a 5-kW fiber laser in order to evaluate the effectiveness of high power fiber laser as a welding processing tool for welding Ti−6Al−4V with the requirements of the aircraft industry and to determine the effect of welding parameters including laser power, welding speed and beam focal position on the weld microstructure, bead profile and weld quality.
TL;DR: In this article, both conventional and bobbin friction stir welding processes (FSW and BFSW) were employed for joining 10 mm thick extruded AA6005-T6 profiles.
TL;DR: In this paper, a numerical thermomechanical model for friction stir welding of aluminum-copper alloy AA2219 was developed and the model was verified by comparing simulated temperature profile of three different weld schedules (i.e., different combinations of weld parameters in real weld situations).
Abstract: Friction stir welding (FSW) is a solid-state joining process, where joint properties largely depend on the amount of heat generation during the welding process. The objective of this paper was to develop a numerical thermomechanical model for FSW of aluminum–copper alloy AA2219 and analyze heat generation during the welding process. The thermomechanical model has been developed utilizing ANSYS® APDL. The model was verified by comparing simulated temperature profile of three different weld schedules (i.e., different combinations of weld parameters in real weld situations) from simulation with experimental results. Furthermore, the verified model was used to analyze the effect of different weld parameters on heat generation. Among all the weld parameters, the effect of rotational speed on heat generation is the highest.
TL;DR: In this paper, the use of a multipass welding strategy for increasing the bonding area in the dissimilar friction stir lap welding (FSLW) of aluminium to steel is analyzed in current work.