The inhibition of the corrosion of Al, Al-6.61 and Al-Cu in chloride free aqueous media: I. passivation in acid solutions

摘要

The electrochemical behavior of Al, Al-6061 and Al-Cu was investigated in solutions of different pH. The inhibition of the corrosion processes occurring at the electrode/electrolyte interface in solutions of borate Buffers (pH 2) was studied. Molybdates and dichromates show pronounced inhibition action which was Investigated and discussed. X-ray photoelectron spectroscopy (XPS) experiments have shown that Al-Cu alloys Have remarkable Cu peaks on the material surface. Exposure of the different electrodes to solutions of pH2 Containing MoO~2_4-, Cr_2O_7~2- and SO~2_4- with the same concentration leads to the incorporation of Cr and Mo in The passive films matrix whereas sulpher was not incorporated.