Study on MIG-TIG hybrid brazing of galvanised thin sheet

Abstract

To increase productivity when joining galvanised sheet metal, metal inert gas (MIG) and tungsten inert gas (TIG) arc brazing are combined in a hybrid process. This coupling of two arc processes increases brazing speed and reduces weld reinforcement and the tendency to spatter. Because the arcs are 6 mm apart, they influence each other. Therefore, the blowing action is a major challenge in hybrid arc brazing. A current modulation and the optimal relative position of the arcs to each other are compulsory conditions. Selected brazing parameters are tested in order to verify the hybrid arc brazing. Overlap joints are brazed on galvanised sheets. The mechanical-technological properties of the brazed joints are determined. It has been shown that hybrid brazing can achieve significantly higher brazing speed with the same or better brazing quality compared to standard arc brazing. For the realisation of the hybrid arc brazing process, software-controlled welding machines are used, which will replace conventional power sources in the future.