Grain refinement due to grain detachment in electromagnetically stirred AA7020 welds

Abstract For the first time evidence is presented that supports the role of the grain detachment mechanism during grain refinement of aluminium welds as a result of stirring. These grains are localised in the centre of the weld pool and have not been fully melted. The results of energy dispersive spectroscopy analysis of these grains indicate the similarity of their chemical composition to that of the grains in the base metal. This suggests that these grains are the partially melted grains, present at the fusion line, that are brought into the weld pool by the action of stirring.