Structural Characterization of the Rolled and Annealed 7475 Aluminum Alloy

Aluminum alloys have been extensively employed in industrial applications due, among other things, to low cost and small weight. The purpose of this work was to investigate the Vickers hardness, tensile strength (at different temperatures) and microstructure (X-Ray diffraction, scanning and transmission electron microscopy analysis) of the 7475-T7351 aluminum alloy (5.67%Zn, 2.38%Mg, 1.78%Cu and 0.28%Fe + Si) after being submitted to rolling (at room and cryogenic temperatures) and annealing treatments (at 200 and 300 degrees C/15 min). Based on the results, the condition that was just rolled and subsequently subjected to annealing heat treatments (200 and 300 degrees C) showed higher mechanical properties obtained at room temperature and hot (250 and 350 degrees C) tensile test than that were submitted to the intermediate annealing heat treatment between the rolling steps. This fact is possibly due to the intermediate heat treatment, which caused a thickening of the precipitates, and consequently a lower microstructural stability.