In order to provide scientific basis for advanced applications of near eutectic Al-Si-Mg alloys as architectural profiles, a comparative study on the corrosion resistance of an as-extruded near eutectic AI-Si-Mg alloy...In order to provide scientific basis for advanced applications of near eutectic Al-Si-Mg alloys as architectural profiles, a comparative study on the corrosion resistance of an as-extruded near eutectic AI-Si-Mg alloy and AA6063 aluminium alloy was carried out by means of neutral salt spray test. The corroded surfaces of the alloys were examined with optical microscopy and scanning electron microscope （SEM）. Results show that the corrosion type of these two alloys is pitting corrosion. The number of corrosion pits in the AA6063 aluminium alloy is more than that in the near eutectic AI-Si-Mg alloy, but the pits in the latter alloy are much larger and deeper. Because the relatively low polarization resistance of the near eutectic alloy leads to poorer repassivation ability, autocatalytic acidification occurs once a pit forms. Thus, occluded corrosion cells are developed in this alloy.展开更多
基金financially supported by Jiangsu Graduate Student Innovation Program of China(No.CXZZ-0146)the Scientif ic Research Foundation of Graduate School of Southeast University(No.YBJJ1235)
文摘In order to provide scientific basis for advanced applications of near eutectic Al-Si-Mg alloys as architectural profiles, a comparative study on the corrosion resistance of an as-extruded near eutectic AI-Si-Mg alloy and AA6063 aluminium alloy was carried out by means of neutral salt spray test. The corroded surfaces of the alloys were examined with optical microscopy and scanning electron microscope （SEM）. Results show that the corrosion type of these two alloys is pitting corrosion. The number of corrosion pits in the AA6063 aluminium alloy is more than that in the near eutectic AI-Si-Mg alloy, but the pits in the latter alloy are much larger and deeper. Because the relatively low polarization resistance of the near eutectic alloy leads to poorer repassivation ability, autocatalytic acidification occurs once a pit forms. Thus, occluded corrosion cells are developed in this alloy.
