Comparative study of corrosion resistance for 6063 and 3003 aluminium alloys in chloride medium

摘要

It is known that aluminium alloys naturally form oxide-hydroxyde film in neutral medium. Nevertheless, corrosion rate has tendency to increase when the neutral medium pH increase or decrease (1-2). Corrosion resistance of aluminium alloys hardly depends upon the medium aggressivity (3-10). SO_4~(2-) has a minor effect on the pitting corrosion of 6000 and 3000 familly aluminium alloys (11-13). However, Cl~- ions are well-known to cause attack on surface and then lead to pitting corrosion (3-6). The corrosion resistance of aluminium alloy depends not only on corrosive medium, but also on the nature and chemical composition of alloy itself (14-15). In this work we present comparative study of corrosion resistance for 6063 and 3003 aluminium alloys in chloride medium. The effect of pH, temperature and chloride concentration are investigated.