## 1 Introduction
Moreover, research identified the twist angle, the twist zone length, and the reduction area as critical optimization variables to maximize process efficiency and minimize pressing load [26]. However, a detailed literature review revealed that experimental work on VE has so far been limited to a specific configuration with a 60\({}^{\circ}\) twist angle and 10 mm vortex zone length [25]. To enhance the efficiency of classical SPD processes, another procedure involves integrating the various SPD techniques into a single die, referred to as hybrid or combined SPD techniques. In general, a hybrid die combines multiple SPD techniques into a single die, allowing for simultaneous pressing of the material. This approach merges the advantages of two or more SPD methods, resulting in a product with significantly improved homogeneity and enhanced mechanical properties. Some of these combined SPD techniques are the following: twist channel angular pressing (ECAP + TE); TE and ECAP processes have been integrated into a single die [38]. Forward extrusion ECAP (FE-ECAP) combines extrusion and ECAP in a single die [39; 40], TV-CAP (Twisted Variable Channel Angular Pressing) consists of adding a twist and extrusion zones to the classic ECAP die channels [9; 10]. Aluminum alloys such as AA6082 have proven to be a popular choice in SPD studies due to their favorable mechanical properties and response to grain refinement processes. Researchers have extensively explored the alloy AA6082 in various SPD methods, establishing its significance in material science. [PERSON] et al. (2019) demonstrated that ECAP under warm conditions led to refined grain structure and increased strength in AA6082; although, softening occurred after multiple passes [41]. [PERSON] et al. (2016) focused on the combined effect of ECAP and aging, achieving substantial improvements in yield strength and hardness [42]. [PERSON] et al. (2021) explored the ECAP bonding process with AA6082 and MgAZ31B, revealing challenges in dissimilar material bonding due to differences in ductility and emphasized the importance of route selection and die design in optimizing mechanical properties [43]. Although a variety of techniques exist, as mentioned in the details above, further refinement and modernization are required for wider applications. When the literature is examined as mentioned above, it is seen that one of the attractive SPD methods is VE. And due to the limited optimization and experimental studies on VE in the literature, it is believed that more comprehensive optimization research is necessary to increase the technique's efficiency. Hence, this paper aims to achieve significant advancements in the field by introducing a novel die design called Vortex Extrusion-Equal-Channel Angular Pressing (Vo-CAP). This novel die combines VE and ECAP into one unified system to harness the advantages of both methods. In order to achieve this goal, the first step was to model the Vo-CAP die and carry out a Finite Element Analysis (FEA) using the DEFORM-3D software (Version 11.0). The obtained results were compared with the literature, and the efficiency and applicability of this novel method was investigated. Later on, to enhance the process efficiency, specific design variables were optimized. The optimized die was manufactured, and the AA6082 material was used as workpiece material. Furthermore, hardness and tensile mechanical tests were carried out to examine the mechanical properties and were compared with annealed workpieces and the literature. Moreover, microstructural analysis was conducted by Optic Microscope (OM) images.