Design and Analysis of Ultrasonic Assisted Friction Stir Welding

Abstract

This paper presents ultrasonic assisted friction stir welding (UaFSW), which is suggested to improve the weld quality and efficiency as a hybrid welding system. Ultrasonic-assisted processes have been coupled with tooling in various manufacturing processes to enhance the performance of conventional machining and bonding processes. For successful and effective implementation of the UaFSW, we must first consider how to integrate ultrasonics into the friction stir welding equipment. To solve this problem, we designed an ultrasonic horn to vibrate the FSW tool and transmit ultrasonic energy into the workpiece. Using a numerical modal and harmonic analysis, we fabricated and analyzed the ultrasonic horn under specific design considerations. Force was measured and compared during ultrasonic assisted and conventional friction stir welding. The mechanical properties of the workpieces were also investigated.

Experimental Investigation on Joining Dissimilar Aluminum Alloy 6061 to TRIP 780/800 Steel Through Friction Stir Welding

“…On the other hand, lateral moving force F x increased rapidly but after certain period of fluctuations also reached to a stable state. Compared with the works of Trimble et al [21], Soundararajan et al [22], and Park [23] where similar aluminum alloys were friction stir welded, three differences in the force curves can be observed. First, only one peak axial force existed during the plunge stage for welding dissimilar materials, whereas two peaks occurred for welding same aluminum alloy.…”

“…Peak axial force was generated as the tool shoulder abraded against steel surface. Second, when welding similar aluminum alloys, axial force F z can be greatly reduced by 35-60% [21,23] during welding stage whereas no more than 20% reduction can be observed when welding Al to TRIP steel. Finally, lateral moving force F x , which is the forced required for translating FSW tool along weld line, was negligible when welding aluminum.…”

Experimental evaluation of ultrasonic-assisted friction stir process effect on in situ dispersion of multi-walled carbon nanotubes throughout polyamide 6

“…Roylin et al [6] studied FSP temperature in presence and absence of ultrasonic vibrations for aluminum 2024. Their findings indicated that temperature of the stirred zone in both simple and ultrasonic-assisted FSP was almost the same, and ultrasonic vibrations did not significantly affect temperature of the stirred zone in lower traverse speed (150 mm/min).…”

“…Heretofore, the literature contains little information about the UAFSW and UAFSP of polymers. Park [5,6] studied the effect of ultrasonic vibration on FSW of Al 6061. He introduced ultrasonic vibration to the workpiece through FSW tool and in its traverse direction.…”

Electrically assisted friction stir welding for joining Al 6061 to TRIP 780 steel

“…According to their results, transverse tensile strength can reach 93% of the base aluminum alloy and the joint elongation can be significantly increased with a ductile fracture mode. Park (2009) developed an ultrasonic assisted FSW process and reported that ultrasonic vibration can help eliminate the wormhole defect at the weld root. Grant et al (2005) implemented an induction heating system in front of the FSW tool and obtained great reduction of loadings on the tool.…”