Ultrasonic seam welding system using a complex vibration circular disk in transverse and torsional vibrations

Ultrasonic seam welding of metal plate specimens using a 28 kHz complex vibration disk welding tip vibrating in transverse and torsional vibration modes is studied. Conventional ultrasonic seam welding equipment using one-dimensional vibration locus can only join metal foil or very thin plate specimens and not join thick metal plate specimens. Using a complex vibration welding system with a welding tip vibrating in elliptical or circular locus, thick plate specimens can be welded with a more uniform and larger area weldment compared to a conventional ultrasonic welding system. An ultrasonic seam welding system consists of a complex vibration disk welding tip which is driven by a longitudinal vibration system through a longitudinal-torsional vibration converter. The disk welding tip vibrates in elliptical locus. Aluminum plate specimens 0.3 mm and 3.0 mm in thickness were successfully joined with such weld strengths that the specimens were broken at the plate parts adjacent to the welded area under tensile strength test. Aluminum plates 50 mm in width were successfully joined by the ultrasonic seam welding system.