Gas Metal Arc Lap Joining of Aluminium Alloys and Steel Sheets

A coupled experimental and theoretical investigation on joining of aluminium and galvanized sheets in lap joint geometry using an advanced pulsed current gas metal arc based process is presented. The experimental study was focussed on finding suitable processing conditions to restrict the heat input, and minimize the growth of the phase layer thickness and the formation of Fe-Al intermetallic compounds along the joint interface. The theoretical study included the development of a three-dimensional heat conduction model to compute the temperature field and thermal cycles, and estimate the final joint bead profiles and phase layer thickness as a function of processing conditions. The estimated results are tested extensively for a wide range of experimental conditions. The experimentally measured and the corresponding computed results show that the dissimilar material combinations of aluminium and galvanized steel can be joined successfully by pulsed current gas metal arc with a precise control of processing conditions and heat input. Key words: Gas metal arc welding, Aluminum alloy, Galvanized steel, Numerical modelling