Microstructure, texture and mechanical properties of continuous cast AA 5083 aluminium alloy

Continuous cast AA 5083 aluminium alloy hot band with and without prior heat treatment at 510°C for 3 h was cold rolled to a reduction of 70% and annealed at 399°C for 3 h. It was found that the alloy without the prior heat treatment showed a strong {113}〈110〉 texture component after the thermal mechanical treatment, while with the prior heat treatment its recrystallisation texture was almost random. The alloy with the prior heat treatment exhibited a fine equiaxed grain structure after annealing, in contrast to a coarse elongated one in the alloy without the prior heat treatment. The tensile properties and their isotropy of the alloy were greatly improved by the prior heat treatment. The concurrent precipitation effect was likely to be responsible for the formation of the new texture and inferior mechanical properties of the alloy. Precipitates of 20 nm in size were observed interacting with dislocations in this alloy.