A strength-model for laser joined hybrid aluminum-titanium transition structures

Besides aluminum (Al) and titanium (Ti) alloys carbon fiber reinforced plastics (CFRP) are increasingly demanded for modern aircraft structures. Therefore, suitable Al-Ti and Al-CFRP joining techniques are of great interest. A novel concept for Al-CFRP joints uses titanium laminates as transition elements. In this paper, the tensile strengths of double-sided laser beam joined hybrid structures of aluminum sheets and single-layer as well as multi-layer titanium parts are investigated by varying the edge shape and the laminate build-up. The full-double-15°-scarf-edges produce the maximum strength. It is shown that a model can explain and predict the different failure behaviors and strengths.