## 3 Results and Discussion
### Scanning Electron Microscopy  
The main aim of the metallographic analysis was to evaluate the microstructures of the solid-state-recycled and conventional specimens welded with different procedures. The microstructure significantly affects the resistance to solidification cracking and mechanical properties of welds [34]. For the metallographic analysis, an FEI Quanta 250 FEG scanning electron microscope (SEM) and Oxford PentaFET energy-dispersive X-ray spectroscopy (EDX) were used. Samples were etched for 20 s at room temperature with a Keller reagent. Figure 6 shows the microstructures of the base material for the conventional and SSR specimens after the hot rolling process. According to Figure 6, the microstructure of the SSR specimen was similar to the conventional one. The microstructure of the recycled sample was very homogeneous, and there were no visible cracks, voids, or porosity. However, a visible chip boundary was detected for the SSR specimen, which confirms the conclusion from the macrostructural and mechanical properties analysis. According to previous microstructural investigations of EN AW 6082 aluminum alloy, Al-Mg-Si phases (usually characterized as Al(FeMn)Si and MgSi) can usually be distinguished [17; 42; 43]. Since both samples in this investigation were in the annealed condition, the principal strengthening precipitates, Mg-Si phase particles, \begin{table}
\begin{tabular}{c c c c} \hline \hline  & \multicolumn{3}{c}{**Tensile Strength (MPa)**} \\ \hline
**Specimen Type** & **MIG** & **TIG (One Side)** & **TIG (Two Sides)** \\ \hline
**SSR** & 178.5 & 64 & 120 \\
**Conventional** & 188.5 & 72 & 132 \\ \hline  & \multicolumn{3}{c}{**Engineering Strain (\%)**} \\ \hline
**Specimen Type** & **MIG** & **TIG (One Side)** & **TIG (Two Sides)** \\ \hline
**SSR** & 20.7 & 6.1 & 17.6 \\
**Conventional** & 13.5 & 5.7 & 11.7 \\ \hline \end{tabular}
\end{table} 
Table 3: Tensile test results for the solid-state-recycled and conventional specimens after welding. appeared in the form of coarse precipitates in black, while the bright spots were Al(FeMn)Si phase particles (Figure 7). Visible similar-sized phase particles were homogeneously dispersed inside both samples, which confirms that the obtained conventional and solid-state-recycled sheets had similar microstructural states for the comparative welding analysis. In the weld zone, typical intergranular precipitates were observed, as shown in Figure 8, which, in previous research, were found to contain Fe, Mg, Mn, and Si elements [24]. The formation of \(\alpha\)-Al\({}_{15}\)(Fe,Mn)\({}_{3}\)Si\({}_{2}\) in alloys with added Mn and \(\beta\)-Al\({}_{5}\)FeSi has also been reported [29; 30]. Therefore, the precipitates observed here probably consisted of Si, Mg\({}_{2}\)Si, and \(\alpha\)-Al\({}_{15}\)(Fe,Mn)\({}_{3}\)Si\({}_{2}\) and \(\beta\)-Al\({}_{5}\)FeSi phases. Figure 9 shows the transition zones between the base materials and weld zones. For all specimens, the transition zones were similar, with the base material containing finely distributed intermetallic phases. In the weld material, because of the filler metal's different chemical composition and the metal solidification in the weld zone, characteristic larger intermetallic phases and aluminum dendrites were obtained. In the transition zone and beginning part of the weld zone, some columnar dendrites were visible, while farther from the transition zone, equiaxed dendrites formed. These columnar crystals grow perpendicular to the fusion line, along the direction of the heat flow [34]  
Figure 6: Scanning electron microscope images of solid-state-recycled EN AW 6082 aluminum alloy in the hot-rolled condition: (**a**) conventional and (**b**) SSR specimens. In order to additionally confirm the macroscopic images and above discussion of the behavior of the mechanical properties, Figure 10 was added to the manuscript. In Figure 10a, there is some visible development of microdelamination and, therefore, additional porosity, which were not present in the conventional specimens.