Abstract: During the developing process of a new type drying tunnel of a certain VA washing machine, early corrosion of the drying tunnel was observed. In order to figer out the reason of the corrosion, the corrosion product, microstructure and corrosion mechanism of the aluminum alloy were investigated. The results show that the die casting aluminum alloy was composed of the pre-eutectic α-Al and eutectic (Al+Si); corrosion of the die casting aluminum alloy drying tunnel mainly follows the electrochemical corrosion mechanism, produces Al(OH)₃ and a small amount of AlOOH. The corroded aluminum alloy consists of the remained Si and Fe-rich particles on the surface, which is black and loose. In terms of the reduction of the Fe and Si contents and the optimization of the die-casting technique parameters, the microstructure and the corrosion resistant property of the aluminum alloy drying tunnel could be improved.

Key words: Die casing aluminum alloy, Corrosion product, Corrosion mechanism, Microstucture