Joining of multi-material lightweight structures by power ultrasonicsThursday (09.11.2017) 14:20 - 15:00 Part of:
A central research field of our group is the realization and to study innovative multi-material or even hybrid joints by ultrasonic welding techniques. The talk gives an over-view about suitable ultrasonic welding systems as well as important parameters, which influence the quality and microstructure of dissimilar joints. Besides the well-established spot welding technique also special ultrasonic-based welding techniques like torsion and roll-seam welding will be introduced for joints between dissimilar light metals such as aluminum to titanium as well as lightweight hybrid welds between fiber reinforced polymer composites to automotive and aerospace light alloys. The high fre-quency process (20 kHz) was monitored by online NDT-methods like thermography and laser-vibrometry. All realized multi-material joints were characterized by their me-chanical performance. Furthermore the welded interface as well as fracture surfaces after mechanical loading were investigated in detail by using light optical and electron microscopy (SEM and TEM) as well as spectroscopy (EDX and EELS).