Non-keyhole Friction Stir Welding for 6061-T6 Aluminum Alloy

A novel non-keyhole friction stir welding technique was proposed to weld the butt joint of 6061-T6 aluminum alloy with thickness 6 mm. sound obtained by this technique, simultaneously eliminating flash, shoulder mark and keyhole defects. The sleeve directly affected zone (SDAZ) indirectly (SIAZ) were divided into according plunging position hollow sleeve. lack root penetration defect avoided when depth only 4.2 mm, because part inside improved material flow below An S-shaped line left at SIAZ, height it had minimum value 1.47 mm 20 mm/min. Whether failure location in SIAZ/SDAZ or heat-affected (HAZ) depended on bonding strength line. fracture changed from 35 mm/min HAZ 30 maximum tensile 224.3 MPa which 73.7% that base material. surface morphology exhibited typical ductile fracture.