The influence of pulsation of the MIG arc on the structure of aluminium alloy welds

Abstract

In this article, trends in the development of welding equipment in Japan were discussed. Results of examinations of the influence of MIG welding with both single and double arc pulses on a macrostructure of aluminium welds were presented. It was stated that, because of lower line energy (the so-called cold weld pools), welding with a double pulse has the most disintegrated crystalline structure. Welding with a single pulse results in a crystalline structure in weld reinforcement only, whereas welding without an arc pulse causes formation of very adverse columnar crystals, which increases susceptibility to hot cracking.