72 巻 (2006) 6 号 p. 740-744
This paper describes the elucidation about formation of passivity film on aluminum alloy surface with dilute NaCl electrolytically reduced water. First, the sample of aluminum alloy is immersed in the electrolytically reduced water, and passivity film(Al2O3) is formed on the surface of samples. Next, the chemical composition of passivity film, the relation between thickness of passivity layer and immersing temperature was clarified by using surface analysis of Auger and ESCA (Electron Spectroscopy for Chemical Analysis). Finally, the corrosion resistance of the passivity film by the saltwater immersing experiment was evaluated. As results of the study, following could be identified. (1) Passivity film can be formed to the aluminum alloy with electrolytically reduced water, and the thickness of passivity film as the immersing temperature rises. (2) The immersing condition influences micro shape and surface roughness of passivity film. (3) The crack is generated on passivity film, but if sealing is processed, the crack can be lost. (4) Corrosion resistance improves if passivity film is formed with electrolytically reduced water.