advanced manufacturing engineering by investigation of submerged friction stir welding processes

Submerged friction stir welding (sfsw) is a modification of the friction stir welding process in which the water as the coolant is employed to standardize the temperature. it is considered as a green and environmentally friendly welding technology because of low energy consumption, no gas emission, and no need for consumable material. it is applied to structural purposes like oil platforms and pipelines, or in industrial and laboratories for enhancing the weld strength. sfsw is one of the advanced manufacturing engineering of solid state joining and it is used for welding a wide range of materials. this technique used to the 6061-aluminum alloy joint and it has been demonstrated to be an effective method to improve the mechanical properties of joints. to illuminate the characteristics of sfsw, the microstructural evolution and its effect on mechanical performance of an underwater joint were investigated in the present paper. this work compared the parameters of friction stir welding (fsw) and sfsw on the weld joint. in this investigating fsw used in underwater environment, for this operations research pin covered and shielded from contact water by hollow shaft spin (hss), the hss controlled the heat conduction of pin and disconnect with water, applying for the first time a novel underwater fsw technique developed in various industries. the metallographic exams indicate that weld nugget grain size has been decreased. the mechanical testing illustrated that hardness and tensile strength have been increased, on the other hand the percentage of elongation and impact energy have been diminished.