MIG and CMT brazing of aluminum alloys and steel: A review

Abstract

In automobile industries production of lightweight vehicles to increase the performance of a vehicle, reduction in fuel consumption, and the low emission of toxic gases have generated the need for the fabrication of multi-material design. In recent years an effort was made to fabricate the automobile bodies with dissimilar metals like aluminium and stainless steel but welding or joining of these two different metals is very difficult due to non-identical thermo-physical properties, melting point, zero solubility, and the emergence of hard and brittle intermetallic compound (IMC) and phases at the interface of joint. Different welding and joining processes were attempted to join steel and aluminium to restrict the emergence and growth of hard and brittle IMC phases and their layer thickness at the interface through effective heat control input. Though MIG, CMT-MIG brazing is more effective than any other welding and joining processes due to their control on heat supply and synchronized transfer of molten metal. This study aims to examine the several welding factors in the joining of steel and aluminium by MIG, CMT, and other arc-based welding methods. Various factors such as the impact of heat input, process parameters, and different filler wires on the formation of IMC thickness and firmness of joint are analyzed and discussed.