Influence of anodic oxide film structure on adhesive bonding performance of 5754 aluminum alloy
(Chinalco Material Applications Research Institute Co., Ltd., Beijing 102209, China)
Abstract: Three types of anodic films (unsealed, hot water sealed and agent sealed) were prepared to study the effects of anodic film structure on the adhesive bonding performance of AA5754 automotive sheets. The morphology of the anodic films was examined by using scanning electron microscope (SEM) and the composition was examined by glow discharge optical emission spectroscopy (GDOES). The adhesive bonding strength and the durability in corrosive environment were investigated by using single lap-hear test and salt spray test (SST), respectively. The results showed that the unsealed sample could provide high initial bonding strength, but the durability was poor in corrosive environment. The hot water sealed sample could provide high durability, but the bonding strength was low. In contrast, the agent sealed sample displayed porous structure at outer layer and partially plugged nano pores structure at inner layer, providing both excellent bonding strength and durability.
Key words: anodizing; sealing agent; glow discharge optical emission spectroscopy (GDOES); lap-shear; bonding