Effect of the axial external magnetic field on copper/aluminium arc weld joining

Pure copper and aluminium alloy was joined by cold metal transfer welding with the assistance of an axial external magnetic field in this work. The results reveal that magnetic field led to a reduction of the average heat input and improved the wetting behaviour of the weld metal on the copper sheet surface. The thickness of the Al2Cu intermetallic compound layer formed at the interface was decreased from 50 µm for normal welding to 5 µm for the magnetic field-assisted welding process. The joint strength was observed to increase with the magnetic field. For a 21 mT and 10 Hz magnetic field, the maximum loading force reached up to 1.67 kN, resulting in an increase in joint strength by 33%.