Influence of Dispersion Hardening and Severe Plastic Deformation on Structure, Strength and Ductility Behavior of an AA6082 Aluminum Alloy

An AA6082 aluminum alloy reinforced with small additions of Al2O3 (0.2 wt.%) nanoparticles has been. The introduction of a powder master alloy in a metallic melt was carried out by simultaneous ultrasonic exposure and mechanical mixing. Furthermore, samples from the ingots of a reference alloy and a dispersion-strengthened alloy were subjected to a repeated severe plastic deformation (SPD) by using equal channel angular pressing at a temperature of 493 K. After SPD processing, an alloy structure was extensively worked. The presence of nanoparticles contributes to the formation of a more homogeneous and fine-grained structure in the composite after SPD treatment as compared to the reference alloy. We investigated the combined effect of dispersion hardening and SPD processing on the change of mechanical properties and plastic flow behavior of alloys. We found that the microhardness, yield strength, and ultimate tensile strength showed a sharp rise with a simultaneous increase in elongation before the fracture. Before and after the SPD treatment, the effect of increasing mechanical properties in the dispersion-hardened alloy was more pronounced than in the reference alloy.