Deformation Mechanism in Mechanically Coupled Polymer–Metal Hybrid Joints

Abstract

In this, work, metal inserts were joined with polyamide 6 by using the injection-molding technique. The metal parts, made of steel grade DC 04, were mechanically interlocked with polyamide 6 (PA6) by rivets as a mechanical connection between both components in the form of s polymer filling the holes in the metallic parts. The mechanical-interlocking joints made of steel/PA6 were mechanically tested in a tensile-lap-shear test. The damage behavior of the joined materials in relation to rivet number and position on the metal plate was studied. The observation of rivet deformation was also conducted by infrared IR thermography. The study showed that, for polymer–metal joined samples with fewer than three rivets, the destruction of rivets by shearing meant sample damage. On the other hand, when the polymer–metal joint was made with three or four rivets, the disruption mechanism was mostly related to the polymer part breaking. The maximal values of the joint’s failure force under tensile-shear tests were achieved for samples where three rivets were used. Moreover, strong correlation was found between the surface temperature of the samples and their maximal force during the tensile-lap-shear test.