Ultrafine-grained (UFG) materials, which are obtained via severe plastic deformation (SPD) processes, exhibit significantly improved mechanical properties compared to their coarse-grained counterparts. Nevertheless, one of the main disadvantages of UFG materials is their reduced thermal stability, resulting from high stored energy and highly deformed structure. As a result rapid grain growth at elevated temperature occurs. This phenomenon is particularly unfavorable in the case of welding, which is one of the elementary processes in the industry. Therefore, UFG materials require advanced joining techniques in order to maintain their properties. In the present study, two techniques were chosen to investigate their suitability - friction stir welding and electron beam welding. Two materials were chosen, commercially pure aluminium and Al-Mg-Si alloy. Both of them were welded in an undeformed state and after SPD processing. The main focus has been put on a microstructure evolution, but also mechanical properties. The changes in particular zones have been investigated, and two techniques were compared.