The Effect of Nucleation Sites for Recrystallisation on Annealing Texture and Earing in Aluminium

Abstract

It is important to control the recrystallised texture in the aluminium alloy used for beverage cans. A model has previously been proposed which explains the recrystallised texture of the hot bands as a competition between grains nucleated either in transition bands or around coarse particles. Present work confirms that most recrystallised grains are nucleated around coarse particles and that these do not have any preferred orientation. Possibly the smaller of the coarse particles have a weak tendency to nucleate grains in a retained rolling orientation. Other recrystallised grains not associated with particles are preferably oriented on the (100)-fibre parallel to the rolling direction including the important cube and Goss orientations.A light cold rolling of the hot bands prior to annealing can increase the final cube texture, but only if the hot band is slightly recrystallised. This is explained by a destruction of most small recrystallised grains while a few selected grains are conserved. Recrystallised grains in the vicinity of coarse particles are prone to destruction while grains oriented in the actual cube position for the applied cold rolling reduction are especially apt for conservation.