P 883 – Fixation of bonded multi-material with aluminium combined with high strength steel 22MnB5 by a new technique of riveting
Self piercing solid-riveting in combination with the adhesive technology represents a hybrid joining technology having a high potential for use in particular with regard to the joining of high-strength materials in a composite construction compared with a variety of alternative joining technologies.
With the aim to qualify this method for practical applications for joining thin sheet semi-finished products made of an ultra-high-strength steel with a tensile strength of about 1600 MPa in mixed compounds with aluminium wrought alloys, studies to elementary bonding and self piercing solid-riveting as well as to the combined application of these joining technologies were conducted in this research project.
Central subject of the studies is to change the principle of the self piercing riveting tools and auxiliary joining elements from the present cause-effect relationships in such a way that critical deformations of the joining parts can be avoided and an optimized adhesive connection can be achieved. An one-piece die concept is maintained here, which is optimized by an adapted basic form. The use of a supporting ring around the die in combination with a flat-head rivet shows a significant improvement of the quality of the connection. The use of two different adhesives showed the robustness of the modified process variant.
The efficiency of the achieved optimizations is further illustrated by studies on the structural behaviour of elementarily and hybridly joined connections under static and dynamic force transmission. So, for instance, the energy absorption capacity for connecting 1,5 mm 22MnB5 with 1,15 mm AA6014 could be more than doubled compared to the conventionally joined compound. The given strength potential of the aluminium material is almost fully used as a result.
Recommendations for the constructive and manufacturing technical handling of the process are derived from the obtained findings in conclusion.
The research project IGF-No. 16789 N from the Research Association for Steel Application was supported by the Ministry of Economic Affairs and Energy through the German Federation of Industrial Research Associations (AiF) as part of the programme for promoting industrial cooperative research (IGF) on the basis of a decision by German Bundestag. The research project has been carried out at Laboratorium für Werkstoff- und Fügetechnik der Universität Paderborn.
Only available in german language.
O. Hahn, G. Meschut, M. Matzke