Internal Flow Behaviour and Microstructural Evolution of the Bobbin-FSW Welds: Thermomechanical Comparison between 1xxx and 3xxx Aluminium Grades

Abstract The influences of processing parameters and tool feature on the microstructure AA1100 AA3003 aluminium alloys were investigated using bobbin friction stir welding (BFSW). research includes flow visualization microstructural evolution weld texture metallographic measurement method. Results indicated that operational (e.g. feed rate, rotating speed) geometry can directly affect patterns structure. microscopic details revealed by optical electron microscope imply dynamic recrystallization including grain refinement precipitation mechanisms within stirring zone region. observations for samples show a better performance fully-featured (tri-flat threaded pin scrolled shoulders) compared to simple without inscribed surface features. resulted in more uniform thermomechanical plastic deformation structure along with hardening homogeneity microstructure.