Mohammad Sadeghi - Post Ph.D. of Materials Engineering, Department of Materials Engineering, Karaj Branch,Islamic Azad University, Karaj, Iran
Hamed Sabet - Associate Professor, Department of Materials Engineering, Karaj Branch, Islamic AzadUniversity, Karaj, Iran
Maziar Farahani - M.Sc. of Materials Engineering, Department of Materials Engineering, Baker Hughes a GECompany, Australia

Submerged friction stir welding (SFSW) is a modification of the friction stir welding processin which the water as the coolant is employed to standardize the temperature. It is consideredas a green and environmentally friendly welding technology because of low energyconsumption, no gas emission, and no need for consumable material. It is applied to structuralpurposes like oil platforms and pipelines, or in industrial and laboratories for enhancing theweld strength. SFSW is one of the advanced manufacturing engineering of solid state joiningand it is used for welding a wide range of materials. This technique used to the ۶۰۶۱-aluminumalloy joint and it has been demonstrated to be an effective method to improve the mechanicalproperties of joints. To illuminate the characteristics of SFSW, the microstructural evolutionand its effect on mechanical performance of an underwater joint were investigated in thepresent paper. This work compared the parameters of friction stir welding (FSW) and SFSWon the weld joint. In this investigating FSW used in underwater environment, for this operationsresearch pin covered and shielded from contact water by hollow shaft spin (HSS), the HSScontrolled the heat conduction of pin and disconnect with water, applying for the first time anovel underwater FSW technique developed in various industries. The metallographic examsindicate that weld nugget grain size has been decreased. The mechanical testing illustrated thathardness and tensile strength have been increased, on the other hand the percentageof elongation and impact energy have been diminished.

Advanced manufacturing; submerged; friction stir welding