Initiation of abnormal grain growth in cold-rolled sheet of AA5182 Al-Mg alloy: role of texture

Abstract

In this work, we investigate the role of crystallographic texture on the onset of abnormal grain growth (AGG) in AA5182 alloy. TMP included 65% cold-rolling reduction and isothermal annealing at 480°C at various times. The microstructure characterization by optical microscopy in polarized light revealed that AGG starts after holding for 5 min at 480°C. Further investigation of the sample with incipient abnormal grains was conducted by an SEM equipped with an EBSD detector. The incipient abnormal grains appear to have an orientation of minor texture components, i.e. different cube variants, most likely due to the enhanced grain boundary mobility. However, texture fails to explain the difference in the propensity toward AGG in the region close to the sheet surface and its center, which is likely caused by the non-uniform distribution of the intermetallic particles.