Interface Adhesion Characteristics of Carbon Fiber Reinforced Polymer Laminates Bonded to Aluminum With Different Surface Treatments

ABSTRACT Dissimilar material bonding of carbon fiber reinforced polymers (CFRPs) and aluminum alloys (AA) has become widely used in different industries because it offers advantages such as lightweight, high strength from CFRPs, and impact resistance from AA. This work investigated the combined effects of different AA types, AA surface treatments, CFRP resin contents, and CFRP fabric types on the peel strengths of CFRP–AA bonding joints by conducting 90° peel tests. The results showed that the bonding joints composed of anodized AA3003 and unidirectional (UD) CFRP, whose fibers at the bonding interface were perpendicular to the peeling direction, exhibited the highest peel strength of 2.10 N/mm, which is over 10 times larger than that of the joint using untreated AA3003 and UD CFRP. This improvement was attributed to the larger contact area of anodized AA resulting from the denser micropores and the obstacles created by the transverse carbon fibers. The AA type, resin content, and fabric type also had significant effects on the adhesion between AA and CFRP. The findings of this work provide practical insights for optimizing the design and fabrication of CFRP–AA dissimilar material bonding joints.