The topic of this master thesis is optimization of welding technology on aluminium alloy 6082-T6 with AC MIG process. The paper is divided into two parts, the first part is theoretical and the second is experimental. In the theoretical part, the historical development of aluminium is presented in general. The properties, division, and application of aluminium and its alloys are listed. The topic related to the weldability of aluminium and the possible problems that arise during welding was discussed. The consequences of excessive heat intake and inappropriate work techniques are shown. The features of the AC MIG welding process are described and a comparison with the conventional MIG process is presented. In the experimental part, suitable welding technology of aluminum alloy 6082-T6 with minimal heat input for butt joints was chosen for the appropriate thicknesses of the base material. The geometry of the preparation as well as the maximum interpass temperature were defined. The welding of workpieces was carried out using the AC MIG welding process with mechanized motion and the use of shielding argon gas. Welded joints were tested, and the results were analyzed according to the HRN EN ISO 15614-2 standard. In conclusion, the optimal AC MIG welding technology is defined from the point of view of the geometry and mechanical properties of the joints. After considering the theoretical and experimental parts, the test result was analyzed and conclusions were made.