Multi material ultrasonic joining using microstructured joining partners

摘要

The trend towards lightweight construction leads to an increased use of lightweight materials such as aluminium alloys and fibre-reinforced plastics with a thermoplastic matrix. An adequate joining technology for these material combinations is ultrasonic welding. It is distinguished by a broad spectrum of weldable materials and material combinations. Besides joining parameters, the surfaces of the joining partners are crucial for the joint strength. Especially topography influences many physical and mechanical joining mechanisms. These effects can be intensified by a systematic microstructuring of the joining partners. Within this work, the ultrasonic welding of the aluminium alloy 5083 and thermoplastic carbon fibre-reinforced plastics (TPU) matrices was investigated. The study is based on a statistical experimental methodology that allows for a reduction of the experimental effort. Depending on joining parameters and different surface topographies of the aluminium surfaces, higher joining strength can be achieved in comparison to unstructured aluminium. The quality of the welds was evaluated in tensile shear tests. For an understanding of the mechanical properties, accompanying microstructural studies of the welded hybrid composites were carried out and described.