Resistance spot welding of aluminium material with alternating current - Suitability of older welding machines

摘要

A number of organizations still have old alternating current resistance spot welding machines - many manufactured in the former GDR. They were used predominantly for the welding of steel. Since today the demand is primarily for light metal constructions, we investigated the question of whether and to what extent these machines can also be employed in the spot welding of aluminium. Welds were made with alternating current on a series of old spot welding machines and some welds with direct current for comparison. For the evaluation and quality assurance of the spots a draft standard was compiled. From this, a list of weld parameters was prepared and a classification of the spot welds by grades undertaken as a function of the machine type and of the metal thickness.