scholarly journals Development of Resistance Spot Welding Processes of Metal–Plastic Composites

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3233
Author(s):  
Paweł Kustroń ◽  
Marcin Korzeniowski ◽  
Tomasz Piwowarczyk ◽  
Paweł Sokołowski
Keyword(s):  
Resistance Spot Welding ◽  
Spot Welding ◽  
Electrical Contact ◽  
Weight Ratio ◽  
Polymer Layer ◽  
Plastic Layer ◽  
Application Range ◽  
Resistance Spot ◽  
Plastic Composites ◽  
Welding Processes

Metal–plastic composites (MPCs) are gaining importance mainly due to high strength to weight ratio. They consist of three layers, two outer metallic cover sheets, and a plastic core. The presence of that inner plastic layer makes them rather unsuitable for joining by means of any conventional welding processes, which significantly reduces the application range of MPC. In this work, three various resistance spot welding (RSW)-based concepts were developed to overcome that limitation and join Litecor to DP600 steel. In all cases, a dedicated initial stage was implemented to RSW, which was aimed at removing the non-conductive polymer layer from the welding zone and creating the proper electrical contact for the resistance welding. These were, namely: (i) shunt current-assisted RSW; (ii) induction heating-assisted RSW; and (iii) ultrasonic-assisted RSW. The development of each concept was supported by finite element modeling, which was focused on setting the proper process parameters for polymer layer removal. Finally, the macro- and microstructure of exemplary RSW joints are shown and the most common spot weld features as well as the further development possibilities are discussed.

A Comparative Study of AC and MFDC Resistance Spot Welding

2004 ◽  
Author(s):  
Wei Li ◽  
Daniel Cerjanec
Keyword(s):  
Comparative Study ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Process ◽  
Welding Current ◽  
Median Frequency ◽  
Resistance Spot ◽  
Secondary Voltage ◽  
Nugget Growth ◽  
Welding Processes

This paper presents a comparative study of the AC and MFDC resistance spot welding process. Two identical welders were used; one with a single phase AC and the other with a median frequency DC weld control. Both welders were instrumented such that the primary and secondary voltage and current could be collected. A nugget growth experiment was conducted to compare the weld size and energy consumption in the AC and MFDC welding processes. It is found that the MFDC process generally produces larger welds with the same welding current. However, this difference is more prominent when the welding current is low. Overall the AC welding process consumes more energy to make a same size weld. The larger the welding current is used, the less efficient the AC process becomes.

A Microscopic Approach to Determine Electrothermal Contact Conditions During Resistance Spot Welding Process

2008 ◽  
Vol 131 (2) ◽  
Author(s):  
P. Rogeon ◽  
R. Raoelison ◽  
P. Carre ◽  
F. Dechalotte
Keyword(s):  
Resistance Spot Welding ◽  
Spot Welding ◽  
Electrical Contact ◽  
Welding Process ◽  
Contact Temperature ◽  
Macroscopic Model ◽  
Contact Conditions ◽  
Imperfect Contact ◽  
Resistance Spot ◽  
Nugget Growth

This study deals with resistance spot welding process modeling. Particular attention must be paid to the interfacial conditions, which strongly influence the nugget growth. Imperfect contact conditions are usually used in the macroscopic model to account for the electrical and thermal volume phenomena, which occur near a metallic interface crossed by an electric current. One approach consists in representing microconstriction phenomena by surface contact parameters: The share coefficient and the thermal and electrical contact resistances, which depend on the contact temperature. The aim of this work is to determine the share coefficient and the contact temperature through a numerical model on a microscopic scale. This surface approach does not make it possible to correctly represent the temperature profiles, with the peak temperature, observed in the immediate vicinity of the interface and thus to define, in practice, the contact temperature correctly. That is why another approach is proposed with the introduction of a low thickness layer (third body) at the level of the interface the electric and thermal resistances of which are equivalent to the electrical and thermal contact resistance values. In this case, the parameters of the model are reduced to the thickness of the arbitrarily fixed layer and equivalent electric and thermal conductivities in the thin layer, the partition coefficient and the contact temperature becoming implicit. The two types of thermoelectric contact models are tested within the framework of the numerical simulation of a spot welding test. The nugget growth development is found to be much different with each model.

Evaluation of the Role of Eddy Current in Resistance Spot Welding

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
M. Abu-Aesh ◽  
Moataza Hindy
Keyword(s):  
Eddy Current ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Process ◽  
Welding Current ◽  
Work Piece ◽  
Resistance Spot ◽  
Precise Prediction ◽  
Welding Processes

Extensive work had been conducted on spot-welding due to its rapidly increasing industrial importance. The resistance spot-welding involves complicated phenomena, as several effects are found in the process, e.g., temperature, surface roughness, pressure, and eddy current effects. Most of the work exerted for analyzing the spot-welding process neglect the effect of the eddy current generated during the flow of the huge welding main current through the assembly of electrodes and work sheets. This work presents an analytical method to investigate the generation of eddy current and to determine the total effective welding current in spot-welding. The current distribution on the work sheet when it is fed by a conducting electrode is also investigated. The obtained current formula is based on electromagnetic principles, where a very strong magnetic field is generated in the core of the electrodes as well as in the materials of work sheets due to the flow of very high amperage. The final resultant effective current is the superposition of the electrode welding current and the induced eddy current in the electrode and work piece assembly. The results offer a viable mathematical model, which can be applied for a precise prediction of the effective value of welding current in spot-welding processes, if applied in a comprehensive model including all involved effects.

Significance of Workpiece Conductivity on Resistance Spot Welding Process Map

2019 ◽  
Author(s):  
Xin Wu ◽  
Jingtao Du ◽  
Wayne Cai
Keyword(s):  
Steady State ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Heat Dissipation ◽  
Operation Mode ◽  
Welding Process ◽  
Process Window ◽  
Welding Condition ◽  
Resistance Spot ◽  
Welding Processes

Abstract Resistance spot welding (RSW) is a sheet metal welding process with broad applications, known to be more suitable for low-conductive materials, such as steels, due to concentrated and steady-state heat generation and retention at the metal interface. However, for high conductive metals such as copper, conventional welding processes in resistance spot welding has not been successful. This paper provides a comparative study of resistance welding among steel, aluminum and copper through mechanistic analyses, i.e., analytical solutions calibrated by finite element analyses. It is found when lower conductivity metals, such as steels, are welded, the applied energy can be more concentrated on the interfaces, and the heat dissipation is relatively slow, so that a close to steady-state welding condition can be reached that provides a wide and robust operation window. For welding highly conductive metals having similar melting temperature as that of electrode, the process window becomes much narrower or does not always exist without additional conditioning of materials, design or the welding processes. The physics of RSW process is analyzed based on energy equilibrium, and a new concept of pulse welding process is proposed as a required operation mode for welding copper during temperature ramping up period and prior to electrode melting. A new type of welding limit diagram (WLD) is constructed that contains three welding limit curves (WLC) for nugget formation, and the transient region. The newly constructed WLD allows a clear distinction between welding low- and high-conductive metals, and provides new understanding and a theoretical guidance for widening the weldability window.

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