The influences of chromium-free chemical conversion treatment and anodizing treatment on bonding strength of AZ31 magnesium alloy were studied by lap-shear test, SEM and electrochemical methods. Both chemical conversi...The influences of chromium-free chemical conversion treatment and anodizing treatment on bonding strength of AZ31 magnesium alloy were studied by lap-shear test, SEM and electrochemical methods. Both chemical conversion treatment and anodizing can increase the bonding strength. The anodizing treatment gives higher bonding strength and better corrosion resistance than chemical conversion treatment. The increase of bonding strength by the treatmetlts may be attributed to the uneven surface structures with micro-pores, resulting in increased bonding areas and the embedding effect.展开更多
The correlation between the microhardness and microstructure features of anodic films on 2024 aluminum alloy formed in the mixed sulfuric acid/oxalic acid electrolyte was studied using micro-hardness tester and scanni...The correlation between the microhardness and microstructure features of anodic films on 2024 aluminum alloy formed in the mixed sulfuric acid/oxalic acid electrolyte was studied using micro-hardness tester and scanning electron microscope （SEIVI）. The results show that the microhardness of the anodic film is influenced by the mierostructure of the anodic film such as the film porosity, and the order and continuity of the hexagon columnar ceils. The film microhardness increases as the porosity of the anodic film decreases and the order and continuity of the film ceils increase. With the same current density, as the anodic film thickens with anodizing time, the film microhardness increases because the film porosity decreases and the order and continuity of the cells are also improved. Under the condition of the same anodizing time, as the current density increases, the film microhardness decreases due to the higher film porosity and the poorer order and continuity of the film ceils. The film porosity increases because the increased current density can accelerate the oxidation reaction, strengthen the filed-assisted dissolution and the heating effect in the anodic film, resulting in decreased film order and continuity.展开更多
基金Funded by the Key Project of Science and Technology of Ministry of Education of China(No.108129)
文摘The influences of chromium-free chemical conversion treatment and anodizing treatment on bonding strength of AZ31 magnesium alloy were studied by lap-shear test, SEM and electrochemical methods. Both chemical conversion treatment and anodizing can increase the bonding strength. The anodizing treatment gives higher bonding strength and better corrosion resistance than chemical conversion treatment. The increase of bonding strength by the treatmetlts may be attributed to the uneven surface structures with micro-pores, resulting in increased bonding areas and the embedding effect.
基金Funded by the National Natural Science Foundation of China(No.51210001)
文摘The correlation between the microhardness and microstructure features of anodic films on 2024 aluminum alloy formed in the mixed sulfuric acid/oxalic acid electrolyte was studied using micro-hardness tester and scanning electron microscope （SEIVI）. The results show that the microhardness of the anodic film is influenced by the mierostructure of the anodic film such as the film porosity, and the order and continuity of the hexagon columnar ceils. The film microhardness increases as the porosity of the anodic film decreases and the order and continuity of the film ceils increase. With the same current density, as the anodic film thickens with anodizing time, the film microhardness increases because the film porosity decreases and the order and continuity of the cells are also improved. Under the condition of the same anodizing time, as the current density increases, the film microhardness decreases due to the higher film porosity and the poorer order and continuity of the film ceils. The film porosity increases because the increased current density can accelerate the oxidation reaction, strengthen the filed-assisted dissolution and the heating effect in the anodic film, resulting in decreased film order and continuity.
