The effect of different temperatures on bonding performance of carbon fiber reinforced epoxy composite materials

The threat of global warming and increasing environmental problems have led many producers to take measures. Reduction of carbon emissions is considered as one of the most important measures. Using lighter materials to save fuel has been used by automotive and aviation industry for a long time. Due to lightweight and superior strength carbonfiber reinforced composite materials (CFRP) are used in automotive and aviation industry. In automotive industry these composite materials are commonly bonded with aluminum and similar or dissimilar composite materials by using rivets, adhesives , bolts and screws. In aviation industry composite materials are bonded with titanium for engine-wing assembly. Adhesive bonding is commonly preferred because rivet bonding has negative effect on mechanical performance. In this study, bonding performance of CFRP-CFRP, CFRP-Al, joints were determined under three different temperatures (-80oC, room temperature (23oC), 80oC). The shear stresses of the joints were determined by single lap specimens. Two different adhesives, epoxy and polyurethane based, are used.. For polyurethane adhesive, the shear stress was highest at room temperature and decreased with increasing or decreasing temperature. For epoxy adhesive, when the temperature is increases to 80oC, the adhesion ability gradually decreases. The shear stress was found to be approximately %20 lower in CFRP-Al than in CFRP-CFRP specimens.