Effect of anodizing electrolyte temperature on Al-epoxy bonding strength

Adhesive bonding of aluminum requires activating of surface to improve the adhesion process. A thin layer of anodized aluminium oxide, containing nano-sized pores leads to a strong polymer/metal bond. In this work, an epoxy coating was applied on Al anodized surfaces. A 10 wt.% H3PO4 solution was utilized as an electrolyte. The effect of the electrolyte temperature in the range between 10 -70°C on the adhesion strength was examined using a pull-off method. Surface morphology and topography were identified, using FE-SEM and AFM, respectively. Effects of surface topography on hydrophilic behavior of the nano structured Al anodized layer were investigated using a contact angle test. Changes in the anodizing conditions led to remarkable improvements in adhesion strengths

Keywords:

Anodizing , Electrolyte temperature , Adhesion , Epoxy coating”