The Influence of Nanofillers and Additives on the Adhesion Strength of Aluminum

In this study, adhesives with Al₂O₃ nanofillers or silane additives incorporated have been developed. Functionalization of the Al₂O₃ nanofillers has been carried out to improve the bonding of the fillers to both the adhesive and Al substrate. The silane coupling agents on the nanofillers can react with the Al₂O₃, Al substrate and adhesive through their functional end groups and form strong covalent and hydrogen bonds which can improve the lap shear strength of the adhesive substantially. An improvement in lap shear strength has also been achieved when glycidoxypropyltrimethoxysilane is added directly into Epon 160 adhesive. There is also an obvious change in fracture mode from adhesive to cohesive due to the effect of silane addition which facilitates bond formation between the adhesive and Al substrate.