This study aimed to evaluate the bonding strength in the shear and tensile directions of composite plates bonded by a heat press. These composite plates composed of a carbon fiber reinforced thermoplastic (CFRTP) and an aluminum alloy (A5052). A microstructure was generated on the surface of the aluminum alloy by chemical treatment. We measured the surface free energy associated with the dimple structures of both nano-order and micro-order sizes; we also observed the cross section and bonding interface under a microscope. The effect of the interfacial microstructure on the bonding strength was studied from these results. A strong anchor effect was observed on treatment with large dimples, resulting in a high shear strength. However, the contribution of the anchor effect to the tensile strength was negligible. High tensile strength and surface free energy were observed on treatment with small dimples.
