Effect of surface pretreatment on adhesive bonding and corrosion resistance performance of 5754 aluminum alloy
The 5754 aluminum alloy sheets were prepared in three surface pre-treatment states of rolling annealing state,cleaning state and passivation state according to the require-ments of automobile OEMs.The surface chemical composition,microstructure,roughness and wettability were analyzed,and the effect of surface pretreatment on bonding and corro-sion resistance of the materral was studied.The results show that the surface of the rolled and annealed sample is the loose and porous alumina coating,the surface of the cleaned sample is the nano-scale alumina film,and that of the chemical state sample is the dense nano-scale titanium zirconium thin film.There is little difference in the surface roughness of the three states,the static contact angle with water droplets,in descending order,is rolling annealing state＞passivation state＞cleaning state.The main factor affecting the adhesion performance of 5754 aluminum alloy in different surface pre-treatment states is the surface wetting characteristics.The cleaning-state sample has the best wetting effect and the highest bonding strength.The main factor affecting the corrosion resistance is the compactness of the film.The passivated sample film is the most compact and has the largest capacitive arc radi-us in the electrochemical impedance spectroscopy,which can effectively inhibit the general corrosion and corrosion under the film of 5754 aluminum alloy.The OEMs can comprehen-sively consider the requirements for the pre-treatment of the 5754 aluminum alloy in combi-nation with the requirements for adhesive bonding and corrosion resistance performance.
万方数据
维普
