Thermal Effect during Electromagnetic Pulse Welding Process

Abstract

Magnetic pulse welding (MPW) is a solid state joining process, successfully utilized to join dissimilar metals. This advantage attracted manufacturing industries to fabricate hybrid materials to attain materials with a combination of multiple attributes. The high speed impact during the welding process causes various interfacial phenomena, which have been reported in previous research studies. Combined high speed collision, Joule heating due to eddy current and plastic heat dissipation cause noticeable heating in the workpiece. The heating from the plastic work and collision energy could particularly be significant at the vicinity of the interface compared to other regions of the workpiece. The Joule heating due to eddy current affects the entire workpiece that is prominent before the collision. There is a sharp increase of the temperature at the onset of weld formation due to dissipation of plastic work during the collision. 3D simulations of coupled electromagnetic-mechanical-thermal were carried out to investigate the heating due to the combined Joule heating and plastic dissipation. A case study of MPW, consist of a one turn coil combined with a field shaper, is used to investigate the welding process. The simulations were performed using LS-DYNA®, which has the capability of using both finite and boundary elements to solve the thermo-mechanical problem during electromagnetic forming. The predicted temperature distributions from numerical simulations show expected phenomena of Joule heating and plastic heat dissipation while the analytical approach used to estimate the localized increase in temperature due to supersonic gaseous compression. Minimizing the heating effect by identifying the influencing factors could help to optimize and control the quality of the magnetic pulse welded parts.

Multiphysics Numerical Simulation of the Transient Forming Mechanism of Magnetic Pulse Welding

“…The coupling of the three physical fields of electromagnetic field, structure field and thermal field is involved in the process of MPW. Since the Joule heat generated by discharge is very small, the increase in temperature caused by Joule heat can be ignored [16]. Taking the MPW of an Al-Mg sheet as an example, this paper studies the electromagnetic field distribution of the capacitor bank discharge and the structural field of the Al sheet under the action of electromagnetic force.…”

Hierarchical Morphology and Formation Mechanism of Collision Surface of Al/Steel Dissimilar Lap Joints via Electromagnetic Pulse Welding

“…As the energy dissipates and the collision angle increases, the tremendous quantity of heat arising from severe plastic deformation, Joule heating, collision energy dissipation, and supersonic gaseous compression [20,31,32] give rise to the local melting in the weldingaffected zone or layer IV, accompanied by porous structures and splashed metal debris, as shown in Figure 5. In this stage, the surface tension of melt, dissolved or trapped air, instant high temperature, and pressure provoked by a high-velocity impact (being as high as 1000 m/s [23]) would affect the formation of porous structure and the further interfacial bonding.…”

On Additive Manufactured AlSi10Mg to Wrought AA6060-T6: Characterisation of Optimal- and High-Energy Magnetic Pulse Welding Conditions

“…Simulations and theoretical analyses were performed to understand the formation mechanism of such a morphology and succeeded in reproducing the wave morphology in the Al-Fe interface, and local melt was detected in the weld interface. Sapanathan et al [21] reported the 3D simulations of MP welds: one turn coil combined with a field shaper. The forecast temperature distributions show the phenomena of Joule heating and plastic heat dissipation.…”