Experimental investigation of clinching CFRP/aluminum alloy sheet with prepreg sandwich structure

摘要

Joining dissimilar materials is especially important in the design of hybrid structures, the present research illustrates a new clinching process that differs from the conventional process by introducing a prepreg sandwich structure. Prepreg sandwich structures containing carbon fiber reinforced plastics (CFRP) prepreg and aluminum powder were investigated. Different CFRP prepreg layers were used to evaluate the effect of prepreg thickness on the joinability of clinched joints. The process was applied to join CFRP laminate and aluminum alloy sheet. Lap shear and peeling tests were carried out to verify the mechanical properties of the joints. The interface of joints was observed by metallographic microscope and scanning electron microscope (SEM). Microstructure analysis showed that prepreg can effectively fill the gap caused by plate deformation. Aluminum powder redistributes with resin flow under pressure, and the pressure causes the cold welding effect of the aluminum powder. Mechanical interlocking and resin bonding were combined to enhance the joint reliability. The process provides a new reference for CFRP/aluminum alloy sheet joining.