International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

This paper presents an overview of hybrid technologies for joining dissimilar materials in automotive applications. CMT welding/brazing technology has been experimentally verified for the purpose of joining dissimilar steels or steels and aluminium alloy. Two types of filler material were used, one based on Cu and the other based on Al. When joining dissimilar steels, a true brazed joint was formed, while when joining steels and aluminium, a hybrid – welded/brazed joint was formed. Subsequently, metallographic analysis of the joints and testing of their load carrying capacity was carried out.

The paper provides an overview of the load-bearing capacity of joints of the same and unequal thin steel sheets formed on different pretreated surfaces by adhesive bonding. Four types of surface preparation and rubber-based adhesive were tested. The joints were subjected to a climatic test according to VW: PV1200. The change in the load-bearing capacity of the joints was evaluated on the basis of the force at the joint failure, the type of failure and on the basis of the load to displacement ratio.

The paper is focused on research results of dissimilar materials joining by adhesive bonding. Galvanized and non-galvanized steel sheets with a thickness of 0.8 mm were joined together. To compare the effect of the presence or absence of the Zn layer on the strength of the adhesive joints, control joints were made, consisting only of galvanized and only of non-galvanized materials. The materials were joined on one hand without any surface preparation, and on the other hand prepared by degreasing and mechanical roughening with sandpaper. Epoxy/PVC-Polymerblend adhesive with glass beads was used for bonding to check the thickness of the adhesive. The tensile lap-shear strength was tested according to DIN EN 1465. The joints made of galvanized materials only proved the highest, the joints made of nongalvanized materials only proved the lowest shear strength. The mixed joints did not reach the joint strength of galvanized materials, but exceeded the joint strength of non-galvanized materials. The adhesion of the adhesive to non-galvanized substrates seems to be the limiting factor of the strength of mixed joints