Abstract
Lightweight alloys are becoming more and more important. Based on the 5083 aluminum alloy, the effects of Zn and Cu additions on the microstructures, properties, and serration behavior were investigated. The results show that with the increase of the Zn content, the tensile and yield strengths of the alloy increase, while the elongation and the serration amplitude keep on decreasing. Moreover, different amounts of Cu are added to the high Zn content Al–Mg-6 wt.% (weight percent) Zn alloy, in which the strength and plasticity are improved firstly. When the Cu content was 6 wt%, the elongation of the alloy is about 7%, and the serration behavior of the alloy gradually disappears. The optimal mechanical property is achieved at the composition of Al–Mg-6wt.%Zn-6wt.%Cu. The serration behavior is believed to be related to the interaction between the moving dislocations and the precipitates. Furthermore, the serrated flow was analyzed using the refined composite multiscale entropy algorithm. It was found that the dynamical complexity of the serrations generally increased with an increase in the solute density, the stress-drop magnitude, the grain size, the tensile and yield strengths, and the degree of plasticity.
