Abstract
There is currently high demand on the materials joining involving lap configuration of different thicknesses and sizes in most industrial sectors such as, aerospace, shipbuilding, marine, manufacturing, automobile, aeronautic, railways etc. in which friction stir spot welding actively involved. In the past, industries have been engaging the services of riveting and bolting for such lap joining and which are not effective and as such not reliable because of stress concentration at the joints. Friction stir spot welding is a novel joining technique which relies on heat generated by friction to create a sound welded joint. However, the structural integrity of the joint produced is influenced by the process parameters and materials employed. Hence, this study investigated the effect of selected parameters (rotational speed (600-1200 rpm and dwell time (5-15 s)) on the microstructure and mechanical properties of 5058-H116 Al alloy, FSSW lap joints. The understanding of the structural integrity of the produced joint drives the industrial reliance on the application of this joining process. In this study, a cylindrical tapered, H13 hot working steel tool with a probe length of 5 mm, probe diameter of 6 mm and a shoulder diameter of 18 mm was employed and the tool plunge rate was maintained at 30 mm/min in all trials. Joints produced were subjected to microstructural examination using optical microscope and scanning electron microscope. This research will focus on the characterizations of FSSW fabricated materials and carry out a study on the integrity of the produced welds...
M.Ing. (Mechanical Engineering Science)