Effect of axial external magnetic field on cold metal transfer welds of aluminum alloy and stainless steel

External magnetic field (EMF) is favored for application in welding, due to their positive effects on joint quality. This paper studies the effects of EMF on cold metal transfer welds of aluminum alloys and stainless steel. Results showed that an axial EMF with various magnetic induction intensities and alternating frequency influenced the morphology of a weld arc and molten drop, and ultimately changed the weld microstructure and tensile properties. Application of EMF could suppress the diffusion of Fe to the weld and increased the Si content in the IMCs layer, consequently reducing the thickness of brittle Al/Fe IMCs layers. When the EMF parameter was 2.5 A (17.8 mT) 0 Hz, the maximum load force reached 2.018 kN, which strengthened the joint 45% over an Al/steel joint without the EMF. (C) 2015 Elsevier B.V. All rights reserved.