Aluminum alloys are used in various industries including marine, defense, automotive, transportation and aerospace. Common to all of these industries is the need to join aluminum parts using fusion based welding processes. However, there are some difficulties in welding aluminum alloys, such as, for instance, hot cracking. In this study, the aluminum alloys 5083 and 6061 were welded using the TIG process and two filler wires (AlSi12 and AlSi5). Six different alloy combinations were investigated, i. e., 5083-AlSi5-5083, 5083-AlSi12-5083, 6061-AlSi5-6061, 6061-AlSi12-6061, 5083-AlSi5-6061 and 5083-AlSi12-6061. The mechanical properties of the samples were evaluated by microhardness scans, tensile tests as well as Charpy and three point bend tests. In addition, microstructural investigations were performed by optical microscopy.