optimization of parameters for the friction stir processing and welding of aa1050 aluminum alloy

Friction-stir processing (fsp) was applied on aa1050 aluminum alloy (aa) to find the highestmechanical properties among 28 combinations of the rotational and traverse speed (800-2000 rpm and 50-200mm.min-1) and four different tool probe shapes (threaded, columnar, square and triangle). to this aim, the aastandard sheet went through a single pass of fsp. the 1600 rpm and 100 mm.min-1 with threaded tool probe waschosen as the best combination of rotational and traverse speed. grain size at the stirred zone (sz) was studiedusing optical microscopy (om). the results showed that the sz’s grain size was refined from 30 μm down to about12 μm due to dynamic recrystallization during fsp. the processed sample exhibited improved hardness, yield stress,ultimate tensile strength, elongation up to 65, 80, 66, and 14%, respectively, compared to the annealed aa sample.studying fractographic features by om and field emission scanning electron microscope (fesem) revealed adominantly ductile fracture behavior.