Influence of Welding Parameters on Macrostructure and Mechanical Properties of Friction-Stir-Spot-Welded 5454-O Aluminum Alloy Sheets

Abstract

Friction stir spot welding between 5454 aluminum alloy sheets with the different thicknesses of 1.4 and 1.0 mm was performed. In the welding process, the tool for welding was rotated ranging from 500 to 2500, and plunged to the depth of 1.8 mm under a constant tool plunge speed of 100 mm/min. And then, the rotating tool was maintained at the plunge depth during the dwell time ranging from 0 to 7 sec. The pull-out speed of the rotating tool was 100 mm/min. The increase of tool rotation speed resulted in the change of the macrostructure of friction-stir-spot-welded zone, especially the geometry of welding interface. The results of the tensile shear test showed that the total displacement and toughness of the welds were increased with the increase of the tool rotation speed, although the maximum tensile shear load was decreased. However, the change in the dwell time at the plunge depth of the tool did not produce the remarkable variation in the macrostructure and mechanical properties of the welds. In all cases, the average hardness in friction-stir-spot-welded zone was higher than that of the base metal zone. By the friction stir spot welding technique, the welds with the excellent mechanical properties than the mechanically-clinched joints could be obtained.

Studies on Quality of Joints and Phenomena Therein for Welded Vehicle Components Made of Aluminium Alloy – a Review

“…Choi et al [353] studied spot FSWed joints of sheets made of 5454 alloy (Table 4) with the different thicknesses of 1.4 and 1.0 mm obtained under the TRS in the range from 500 to 2500 rpm, and plunging to the depth of 1.8 mm under a constant tool plunge speed of 100 mm/min. The rotating tool was maintained at the plunge depth during the dwell time ranging from 0 to 7 sec.…”

“…Studying spot FSWed joints of sheets made of 5454 alloys Choi et al [353] found that the enhancement of tool rotation speed changed the macrostructure of the friction-stir-spot-welded zone, especially the geometry of the welding interface. However, the change in the dwell time at the plunge depth of the tool only slightly affected the microstructure of the welds.…”

“…Studying spot FSWed joints of sheets made of 5454 alloys, Choi et al [353] reported that in all cases, the average hardness in the friction-stir-spot-welded zone exceeded that of the base metal zone.…”

Studies on the Quality of Joints and Phenomena Therein for Welded Automotive Components Made of Aluminum Alloy—A Review

“…Studying the spot FSW joints of sheets made of 5454 alloys, Choi et al [417] found that the enhancement of tool rotation speed changed the macrostructure of the friction-stirspot-welded zone, especially the geometry of the welding interface. However, the change in the dwell time at the plunge depth of the tool only slightly affected the microstructure of the welds.…”

“…Choi et al [417] studied the spot FSW joints of sheets made of the 5454 alloy (Table 6) with different thicknesses of 1.4 and 1.0 mm obtained under a TRS ranging from 500 to 2500 rpm and a plunging depth of 1.8 mm with a constant tool plunge speed of 100 mm/min. The rotating tool was maintained at the plunge depth during the dwell time ranging from 0 to 7 s. The pull-out speed of the rotating tool was 100 mm/min.…”