High-Temperature Tensile Mechanical Properties and Microstructure of Rolled 6082-T6 Aluminum Alloy Sheets

Abstract

The tensile properties of rolled 6082-T6 aluminum alloy were tested at a high temperature, and the influences of tensile temperature on its flow stress and anisotropy were studied. The microstructure evolution was characterized using optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). It was concluded that the tensile strength of the studied alloy decreases with increasing temperature. In higher-temperature deformation, the dislocation density decreases alongside the coarsening of precipitates, leading to a decrease in deformation resistance, and increase in the number of dimples and deepening of their sizes, exhibiting good plasticity. The alloy displays anisotropic mechanical properties at 200 °C due to the elongated grains and the orientation of the α-phase. The anisotropy becomes weaker with increasing temperature. There is no evident anisotropy at 400 °C, as the slip systems are activated more easily and the grains begin to recrystallize.

Tensile Behavior and Microstructure Evolution of an Extruded 6082 Aluminum Alloy Sheet at High Temperatures

“…For example, as shown in Figure 4b, at 400 • C, 0.001 s −1 , the peak stresses for 0 • , 45 • and 90 • samples are around 31 MPa. Higher temperature provides sufficient energy to facilitate the recovery and recrystallization processes, the density of dislocation decreases sharply, and the slip is easier to activate; meanwhile, the deformed textures in the original sheet transit to recrystallized texture [30,31]. Therefore, the anisotropy has been weakened or even eliminated.…”