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

Abstract

The hot tensile behavior of an extruded 6082 alloy sheet at varying temperatures and strain rates was investigated by a Gleeble3500 thermal simulation testing machine. The optical microscope (OM), scanning electron microscope (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) were applied to observe the microstructure evolution. It is found that the flow stress of the studied alloy declines with increasing deformation temperature. When deformed at high temperatures, the density of dislocation decreases obviously. In addition, precipitate coarsening occurs, resulting in a decrease in deformation resistance. The dimple number of the fracture samples increases with temperature and the size of the dimple becomes deeper, exhibiting an excellent plasticity. The 6082 sheet presents anisotropy of mechanical behavior at 300 °C, this can be attributed to the fibrous grain and the Brass component {011}<211>. The anisotropic behavior seems to be slighter with an increase in temperature. No obvious anisotropic behavior was found when tensiled at 400 °C. Because it is easier to activate the slip system at elevated temperatures, meanwhile, the recrystallization begins to occur at 400 °C.

Deformation Behavior of an Extruded 7075 Aluminum Alloy at Elevated Temperatures

“…For instance, when the samples were deformed relative to the conditions of 300 °C and 0.1 s −1 , the corresponding yield stress values were 137 MPa, 129 MPa, and 136 MPa for the 0°, 45°, and 90° samples, respectively. Similar trends of mechanical anisotropy have been observed in previous studies, and it was reported that fibrous grains and deformation texture are responsible for this form of regulation [ 31 , 32 ]. During plastic deformations, the grain boundary would hinder the movement of dislocations, and elongated grains result due to the different densities of the grain boundary along three loading directions.…”

“…The experimental data imply that the specimens along the extrusion direction exhibit the maximum strength; meanwhile, the strength of the 90° specimen is the lowest. Qiu [ 31 ] investigated the response of a 6082 alloy processed via extrusion, and it was reported that the specimens along the extrusion direction have the highest stress level. This can be attributed to the elongated grains that formed during extrusion.…”

Effect of Deep Cryogenic Treatment on the Artificial Aging Behavior of 6082 Aluminum Alloy

“…Subsequently, the alloy transitions into the plastic deformation stage, with an increase in stress corresponding to an increase in strain. The formation of a multitude of dislocation tangles and dislocation cells within the alloy leads to an increase in dislocation density [26], and the deformation process is predominantly governed by work hardening. Upon reaching the ultimate tensile strength, the alloy enters a stage where the stress decreases with increasing strain, during which softening behavior becomes more pronounced.…”

Mechanical Properties and Microstructural Evolution of 6082 Aluminum Alloy with Different Heat Treatment Methods

“…The brass texture formed during the cold rolling process accounts for the anisotropy of mechanical properties. Qiu et al [22] investigated the mechanical properties of an extruded 6082 aluminum alloy sheet. The results show that the elongated grain is able to trigger mechanical anisotropy.…”