###### Abstract  
The main aim of this research is to investigate the possibilities and challenges involved in the electric arc welding of solid-state-recycled EN AW 6082 aluminum alloy. Lately, solid-state recycling has gained increased attention as a more sustainable and efficient aluminum recycling method, whereby only about 30% of the energy of conventional recycling is used. This method is based on the deformation of small-sized metal waste into solid recycled specimens without a remelting step. For the welding of solid-state-recycled specimens, both metal inert gas welding and tungsten inert gas welding methods are used. To evaluate the weldability of solid-state-recycled material, welded specimens are compared with welded, commercially produced EN AW 6082 aluminum alloy sheets. The welding is performed using the same processes, parameters, and conditions. To evaluate the welding potential of solid-state-recycled alloy, tensile tests, microhardness tests, optical metallography, and scanning electron microscopy, accompanied by energy-dispersive spectroscopy analysis, are performed. s +
Footnote †: journal: Applied sciences  
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conventional recycling of aluminum alloy machining waste is problematic due to the fact that aluminum is a highly reactive material, and it tends to form aluminum oxide on its surface. This is even more pronounced for lightweight aluminum scrap due to its high surface-to-mass ratio. During the remelting process, this oxide floats on the melting surface mixed with dress. Therefore, aluminum lightweight scrap (chips, foils, and sheet skeletons) is problematic when conventional recycling technology is used, because up to 20% of the aluminum can be lost by the mixing with dress and burning [8]. Therefore, during the conventional recycling process by melting, there is a significant loss of material due to the oxidation of melted metal, but there are also losses due to the inclusion of slags, as well as during the casting and material processing, where the final material yield can be as low as 60% [9; 10; 11]. According to previous research papers concerned with the SSR process, it is possible for the material yield to be over 90% when this type of recycling is employed, while energy consumption can be up to three times less compared to the conventional recycling process, mostly because the remelting phase is completely avoided [12; 13; 14; 15; 16]. Aluminum production accounts for up to 1.5% of global processes and energy-related CO\({}_{2}\) emissions. It is proposed that between 0.13% and 0.22% (51 Mt CO\({}_{2}\)) of global CO\({}_{2}\) emissions could be saved by reusing aluminum machining chips through the mitigation of recycling-associated emissions [5]. Less energy use means a smaller reliance on fossil fuels, reducing the overall carbon footprint, while the absence of melting in solid-state recycling minimizes emissions of greenhouse gases and other pollutants associated with high-temperature processes. It is well understood that the presence of stable oxide films on the faying (i.e., contacting) surfaces of many materials can prevent the achievement of high-quality bonds via diffusion methods. Given the lower ductility of most oxide films, they can rupture when the parent materials are subject to a large amount of plastic deformation [5]. To perform solid-state recycling, severe deformation processes are commonly used, such as hot extrusion, equal channel angular pressing, friction stir extrusion, and spark plasma sintering [17; 18; 19; 20]. [PERSON] et al. [19] showed that critical shear stress should be achieved, whereby the encasing oxide layers break down and enable metal-to-metal contact, which consequently should secure good chip bonding. Also, a critical path length is defined, which is understood as the minimum length of contact by the chip surfaces during the process that is necessary to allow for sufficient welding.