Abstract: In this paper, adhesive bond technique is employed to achieve the bonding of 5182 aluminum alloy used in vehicle body, different surface treatments are adopted to change the surface quality of panel, and the effects of surface parameters such as surface roughness and microscopic surface area on the morphology of joint interface and mechanical properties are studied. The wettability, mechanical properties and the features of fracture surface are analyzed by means of surface free energy measurement, tension / sheer tests and optical microscope measurement. The results show that emery cloth scraping can increase the surface roughness and bonding area of aluminum alloy panels, strengthen the mechanical seizing effects between adhesive and panel, and enhance joint bonding strength. Among them, scraping by P360 can get a greatest enhancement in joint bonding strength, and higher or lower roughness will cause a reduction in effective contact area between adhesive and panel, leading to the lowering of the bonding strength of joints.

Key words: vehicle lightweighting, adhesive bond, aluminum alloy, surface free energy