Study on microstructure, mechanical properties, and texture of the CC AA 3105 aluminum alloy processed by high-pressure heat treatment

The hot band of CC AA 3105 aluminum alloy sheets underwent 6 h of preheating treatment at 599 degrees C. Then, it was cold-rolled to various reductions, followed by 1 h of annealing at 482 degrees C under various pressures. The study investigated the alternation of microstructure, mechanical properties, and texture of these sheets. High-pressure heat treatment (HPHT) remarkably weakens the pinning effect and refines recrystallized grains. In the case of the annealed sheets of which the rolling reduction reached 91.3%, in the atmospheric pressure-to-6 GPa pressure increasing range, the fine precipitates (1-3 nm) disappeared. In contrast, there is an increase in large precipitates and a reduction in the average grain size. Furthermore, the aspect ratio elevated from 0.19 to 0.87, and the average grain size along the rolling direction (RD) reduced from 182.4 mu m to 57.9 mu m. Pressure elevation was accompanied by enhanced strengths of the P and r-cubeND textures but remarkably decreased strengths of the M texture. The elongation of the sheets decreased with increasing pressure. The ultimate tensile strength (UTS), yield strength (YS), and hardness decreased when the pressure rose from atmospheric pressure to 2 GPa and increased in the 2 GPa-to-6 GPa pressure increasing range.