Numerical and Experimental Investigation of Controlled Weld Pool Displacement by Electromagnetic Forces for Joining Dissimilar Materials

Jennifer Heßmann,Kai Hilgenberg,Marcel Bachmann

doi:10.3390/met10111447

Jennifer Heßmann, Kai Hilgenberg + Show 1 more

Open Access

https://doi.org/10.3390/met10111447

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Abstract

In order to reduce CO2 emissions, an increasing interest in lightweight construction exists in the automotive industry, especially the multi-material-design approach. The main construction materials here are steels and aluminium alloys. Due to their different physical material properties and limited mutual solubility, these two materials cannot be joined thermally without difficulty. This paper presents a new joining approach for dissimilar materials. It uses electromagnetic displacement of a laser-generated melt pool to produce overlap joints between 1 mm steel (1.0330) and 2 mm aluminium alloy (EN AW 5754). Contactless induced Lorentz forces are generated by an alternating current (AC) magnet system. The controlled displacement of the aluminium alloy melt into the hole of the overlying steel sheet is investigated through numerical and experimental studies. The numerical results are compared with cross sections and thermocouple measurements. For the first time, it is possible to achieve a reproducible controlled melt pool displacement on thin sheets to produce overlap joints between dissimilar materials.

Highlights

In the last few years, the use of lightweight materials, such as aluminium, has increased continuously in the automotive industry [1]. This has resulted from strict emission regulations to reduce CO2 emissions
A possible solution for this challenge is to reduce the weight of the car, which has resulted in a growing interest in lightweight construction
In addition to the automotive industry, laser beam welding is applied for joining different aluminium alloys for the manufacture of airframes [3]

Summary

Introduction

In the last few years, the use of lightweight materials, such as aluminium, has increased continuously in the automotive industry [1] This has resulted from strict emission regulations to reduce CO2 emissions. In addition to the automotive industry, laser beam welding is applied for joining different aluminium alloys for the manufacture of airframes [3]. The combination of laser beam-induced beam-induced melt melt pool and electromagnetic electromagnetic forces forces can be used to produce a form and firmly bonded joint between dissimilar materials. This joining method is usable for overlap joints, spot and line joints. The are induced into the melt pool without contact and displace the melt upwards while the laser is still

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