الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Nowadays, the need to improve the mechanical properties of aluminum alloys is essential. Therefore, Friction stir processing (FSP) is a new solid-state technique used to improve the microstructural properties and to eliminate the casting and welding defects such as porosity, thereby improving strength and ductility. The present work, two types of welding processes, metal inert gas (MIG) and friction stir welding (FSW) have been used to weld AA5083-H111 aluminum alloy. The study focuses on identify problems in MIG welds and to compare the results with friction stir welding (FSW). In this work, three different tool geometries (pinless, cylindrical and square pin) were developed to study the effect of friction stir processing (FSP) tool geometry on microstructure and mechanical properties of metal inert gas (MIG) welds of AA5083-H111 aluminum alloy. MIG welds, FSW, and FSP joints were evaluated using microstructure investigation, tensile, and hardness tests. The microstructure investigation of FSP joints reveals a very fine grain size in the processed zone, and reduction of weld defects compared to MIG welds. FSP (using pinless tool) of weld surface without weld crown improved the tensile strength when compared with MIG welds. In addition, the processed zone recorded higher hardness values than the base metal as well as the MIG welds of AA5083-H111 aluminum alloy.