Thermal contact conductance effect in modeling of resistance spot welding process of aluminum alloy 6061-T6

Resistance spot welding process is strongly related to interfacial contact behaviors. The effects of thermal contact is rarely investigated so far and generally ignored in numerical models. In this work, a parametric FE model, which considers the variation of the surface roughness of the electrodes and workpieces, has been developed to investigate the effects of thermal contact on weld nugget formation. With the parametric model, four cases, e.g. ideal smooth surface, minimal roughness surface and maximum roughness surface for steel sheets and electrodes of as-received condition, and highly rough electrode surface, are investigated. Researches show that when the surface roughness of the electrodes exceeds some limit, the thermal contact conductance will substantially affect the weld nugget formation, therefore, must be considered in numerical models to precisely predict welding process.

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Friction Stir Resistance Spot Welding of Aluminum Alloy to Advanced High Strength Steel

Journal of Manufacturing Science and Engineering ◽

10.1115/1.4038993 ◽

2018 ◽

Vol 140 (11) ◽

Cited By ~ 3

Author(s):

Kai Chen ◽

Xun Liu ◽

Jun Ni

Keyword(s):

Aluminum Alloy ◽

Resistance Spot Welding ◽

Spot Welding ◽

Plastic Material ◽

Welding Process ◽

Electrical Current ◽

Atomic Diffusion ◽

Friction Stir ◽

Resistance Spot ◽

Welding Force

A hybrid friction stir resistance spot welding (RSW) process is applied for joining aluminum alloy 6061 to TRIP 780 steel. Compared with conventional RSW, the applied current density is lower and the welding process remains in the solid state. Compared with conventional friction stir spot welding (FSSW) process, the welding force is reduced and the dissimilar material joint strength is increased. The electrical current is applied in both a pulsed and direct form. With the equal amount of energy input, the approximately same force reduction indicates that the electro-plastic material softening effect is insignificant during FSSW process. The welding force is reduced mainly due to the resistance heating induced thermal softening of materials. With the application of electrical current, a wider aluminum flow pattern is observed in the thermo-mechanically affected zone (TMAZ) of weld cross sections and a more uniform hook is formed at the Fe/Al interface. This implies that the aluminum material flow is enhanced. Moreover, the Al composition in the Al–Fe interfacial layer is higher, which means the atomic diffusion is accelerated.

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Modeling, identification and simulation of DC resistance spot welding process for aluminum alloy 5182

Journal of Shanghai Jiaotong University (Science) ◽

10.1007/s12204-013-1371-8 ◽

2013 ◽

Vol 18 (1) ◽

pp. 101-104

Author(s):

Liang Gong ◽

Yan Xi ◽

Zhe-ren Ma ◽

Cheng-liang Liu

Keyword(s):

Aluminum Alloy ◽

Resistance Spot Welding ◽

Spot Welding ◽

Welding Process ◽

Resistance Spot ◽

Aluminum Alloy 5182 ◽

Dc Resistance

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Resistance Spot Welding of Aluminum Alloy and Carbon Steel with Spooling Process Tapes

Metals ◽

10.3390/met9040410 ◽

2019 ◽

Vol 9 (4) ◽

pp. 410 ◽

Cited By ~ 4

Author(s):

Seungmin Shin ◽

Dae-Jin Park ◽

Jiyoung Yu ◽

Sehun Rhee

Keyword(s):

Aluminum Alloy ◽

Resistance Spot Welding ◽

Spot Welding ◽

Technological Development ◽

Welding Process ◽

Vehicle Body ◽

Intermetallic Compound Layer ◽

Main Process ◽

Resistance Spot ◽

Grade Steel

Many lightweight materials, including aluminum alloy, magnesium alloy, and plastic, have been used for automotives. Aluminum alloy—the most commonly utilized lightweight metal—has poor resistance spot weldability owing to its inherent properties, which demand the development of welding solutions. Various welding techniques are utilized to improve the resistance spot weldability of aluminum alloy, including DeltaSpot welding. However, the technological development for welding dissimilar metals (aluminum alloy and steel) required for vehicle body assembly is still in its nascent stages. This study proposes DeltaSpot welding (a resistance spot welding process with spooling process tapes) using the alloy combination of 6000 series aluminum alloy (Al 6K32) and 440 MPa grade steel (SGARC 440). The welding characteristics of the main process parameters in DeltaSpot welding were analyzed and the weldability of the combination of the aluminum alloy, Al 6K32, and 440 MPa grade steel was evaluated. In addition, the characteristics of the intermetallic compound layer between the 440 MPa grade steel and Al 6K32 sheets were identified via scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM-EDS).

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Short-Pulse Resistance Spot Welding of Aluminum Alloy 6016-T4 - Part 1

Welding Journal ◽

10.29391/2021.100.004 ◽

2021 ◽

Vol 100 (01) ◽

pp. 41-51

Author(s):

ERIC SCHULZ ◽

◽

MATTHIAS WAGNER ◽

HOLGER SCHUBERT ◽

WENQI ZHANG ◽

...

Keyword(s):

Aluminum Alloy ◽

Resistance Spot Welding ◽

Spot Welding ◽

Short Pulse ◽

Welding Process ◽

Welding Current ◽

Welding Parameters ◽

Resistance Spot ◽

Pull Out ◽

Welding Processes

Short-pulse welding parameters for resistance spot welding (RSW) of aluminum alloy AA6016-T4 using mediumfrequency direct current (MFDC) systems were developed to reduce the heat input required for nugget formation. Optimization of current and time parameters is critical during RSW of aluminum alloys for reducing energy requirements and avoiding weld imperfections, such as solidification cracking and expulsion, while maintaining weld quality, particularly given the high electrical and thermal conductivities of the materials. The welding time and the applied current level of the current pulse were varied systematically for thin sheets (1 mm or 0.04 in.) of AA6016-T4. The quality of the welds was evaluated by pull-out testing, ultrasound testing, and metallography techniques. Simulations of the same welding processes were performed with the finite element-based SORPAS® software. The results showed short-pulse MFDC RSW can reduce the energy required for sound welds in this alloy without requiring an increase in welding current. The simulations and experiments also showed the welding process had distinct weld nugget nucleation and growth phases.

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THERMOMECHANICAL ANALYSIS OF THE RESISTANCE SPOT-WELDING PROCESS

Computational Thermal Sciences An International Journal ◽

10.1615/computthermalscien.2018020490 ◽

2018 ◽

Vol 10 (5) ◽

pp. 449-455 ◽

Cited By ~ 1

Author(s):

Habib Lebbal ◽

Lahouari Boukhris ◽

Habib Berrekia ◽

Abdelkader Ziadi

Keyword(s):

Resistance Spot Welding ◽

Spot Welding ◽

Welding Process ◽

Thermomechanical Analysis ◽

Resistance Spot

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Analysis of Electromagnetic Inverse Model of Resistance Spot Welding

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.160-162.974 ◽

2010 ◽

Vol 160-162 ◽

pp. 974-979

Author(s):

Nai Feng Fan ◽

Zhen Luo ◽

Yang Li ◽

Wen Bo Xuan

Keyword(s):

Resistance Spot Welding ◽

Regularization Method ◽

Spot Welding ◽

Influence Factors ◽

Great Influence ◽

Welding Process ◽

Inverse Model ◽

Resistance Spot ◽

Inversion Theory

Resistance spot welding (RSW) is an important welding process in modern industrial production, and the quality of welding nugget determines the strength of products to a large extent. Limited by the level of RSW quality monitor, however, RSW has rarely been applied to the fields with high welding quality requirements. Associated with the inversion theory, in this paper, an electromagnetic inverse model of RSW was established, and the analysis of influence factors, such as the layout of the probes, the discrete program and the regularization method, was implemented as well. The result shows that the layout of the probe and the regularization method has great influence on the model. When the probe is located at the y direction of x-axis or the x direction of y-axis and Conjugate Gradient method is selected, a much better outcome can be achieved.

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