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Abstract
Friction stir process involves the translation of a rotating cylindrical non consumable tool along the interface between two plates. Heat is generated by the friction between the tool shoulder and workpiece surface. The shoulder is provided to compress the plasticized material and contain the weld region. Friction heats the material which is then extruded around the tool before being forged by large down pressure. The heat generated at the interface between tool and workpiece is the key element to a successful FSW.
FSW advantages result from the fact that the process occurs in solid-state below the melting point of the material to be joined. This enables welding materials that are difficult to weld with fusion welding processes. Applications of FSW includes many fields of industry such as shipbuilding and marine, aerospace, land transportation, construction, electrical industry, and welding of pipes and hollow sections
FSW welding process variables have a direct impact on the behavior of the welding process in terms of weld joint quality and process characteristics. The phenomenon underlying the mechanism of the welding process determines needs to be further investigated through theoretical and expe~imental analysis. It is therefore important to obtain an optimum combination of the welding parameters that lead to the best welding quality
To achieve these goals, an experimental set up on a standard milling machine was prepared using a specially designed welding fixture that is provided with the necessary measuring devices for monitoring and controlling the important process parameters. A series of planned experiments was conducted to test the effect of tool rotational speed (rpm), welding speed {mmlmin}, and welding tool inclination angle on weld properties. Their effects on the weld quality characteristics in terms of tensile strength, hardness, and weld soundeness are analyzed. Welding process behavior was examined in terns of the welding feed force; forge force, stirring force, welding power, and welding temperature associated with the selected welding variables. Optimum welding conditions have been determined with respect to minimum power consumption during welding, maximum tensile strength of the welded joint, and weld soundness.
The FSW process was modeled using ABAQUS software under different welding conditions. The modeling results were related to the experimental results. At the end, conclusions and recommendations for future work are presented.