The principles and applications of friction-stir welding, a solid-state metal joining widely used to weld aluminum and its composites, are assessed. Friction stir processing, a novel process developed for microstructural modification of metallic materials, is also discussed. Academic studies and current sectoral applications of friction stir welding in shipbuilding are examined in detail. In addition, general literature reviews related to the joining of aluminum and steel with friction stir welding are explored. The authors examine past research comparing the friction stir welding and submerged friction stir welding, use of different medium under which the welding is performed, design and process parameters, applications and possibility of future research. In the closing study, a microstructural and statistical approach is performed to obtain a high strength welded joint in the dissimilar friction stir welding of AA 7075 and AA 6013 aluminum alloys.