Effect of adhesive characteristics on static strength of adhesive-bonded aluminum alloys

The use of adhesive is posed to increase dramatically for application to the next generation of vehicle structures as is the use of aluminum. In this study, the effect of adhesive characteristics on the strength of adhesive-bonded lap shear aluminum was investigated. It was found that the joint strength depended on not only the adhesive properties but the bond adhesion between the adhesive and adherend. For the given selected aluminum substrates, to ensure the cohesive failure mode and consistent joint strength it is necessary to select an adhesive which had a weaker than or comparable strength to the bond adhesion. To improve the failure mode from adhesive to cohesive, atmospheric pressure plasma surface treatment of X610-T4PD and X626-T4P aluminum was performed and results showed that it improved not only the joint strength but degree of cohesive failure mode.