Surface treatment of CFRP: influence on single lap joint performances

Nowadays composite materials play a leading role in structural design, particularly in aeronautics and automotive. In these industries, to reduce the weight of the components maintaining the same performance is most required. With this in mind, the use of structural adhesives allows to maximize the specific strength of assembled parts. To have a thorough knowledge of the various influencing parameters is necessary in order to design bonded components. In particular, surface treatments play a key role in joint strength. Understanding the best combinations of adherend - adhesion surface - adhesive allows designing bonded components more easily and reliably. This work analyses the influence of surface treatment of CFRP adherends on mechanical strength and breaking morphology. In particular, SLJ (Single Lap Joints) specimens were made with both film and paste adhesives. It has been noted that the combination between adhesive and surface treatment influenced the failure morphology and mechanical strength.