Influence of the tool probe design on the weldability of Friction Stir Welding butt joints
By Ekaitz Arruti (IK4-LORTEK), Inigo Arin (IK4-LORTEK), Egoitz Aldanondo (IK4-LORTEK), Santiago Zamora (IZAR CUTTING TOOLS)

Tool design is one of the most critical factor in friction stir welding (FSW). The probe geometry directly affects the weldability of the FSW process, which involves the quality of the joints. In this work, two FSW tools with different probe design have been used to weld 8 mm thick AA6063-T5 aluminium alloy sheets in butt configuration. In particular, two probe geometries have been used: threaded cylindrical probes with different pitch and thread inclination. Several process parameter (welding speed and tool rotational speed) combinations have been analysed to define the defect free working window for each probe design, as well as to study the defectology present outside this set of parameters. In addition, the influence of these probe geometries on the welding penetration has been studied, welding 10 mm thick sheets with both tools and analysing the volume of the recrystallized material in the stir zone.