Abstract
The evolution of the recrystallization microstructure at different temperatures and the related change in the microhardness were studied in an Al-6061 alloy after 2 turns of high-pressure torsion (HPT) by means of Vickers microhardness and EBSD analysis. The corresponding results show that HPT processing introduces a significant grain size refinement for the deformed state by comparison with the 150 mu m grain size in the initial material. The microstructure after annealing at 200 degrees C is relatively close to the as-processed structure and the distribution of misorientation angles remains essentially unchanged. However, grain growth takes place at higher annealing temperatures. The variation of Vickers microhardness (Hv) after the different annealing treatments show a gradual decrease when the temperature increases.