Study of electronic properties, mechanical properties and corrosion properties of trace Ce added to Al–Si–Mg–Cu alloys

Abstract

Corrosion and deformation are one of the main causes of material failure in aluminum alloys, which increases the probability of accidents and causes huge economic losses. In this paper, the mechanism of modification of Al–Si–Mg–Cu alloy by Ce addition was investigated. The effects of common elements in aluminum alloys on Ce solid solution were calculated, in which the ability to promote Ce solid solution in Al was in the following order: Cu＞Mg＞Fe＞Ti＞O＞Si. The changes in the properties of the experimental alloys with different Ce contents were investigated by nanoindentation, tensile test and electrochemistry. The results show that the addition of Ce effectively improves the corrosion resistance and strength of the extruded Al–Si–Mg–Cu alloy. However, the addition of excess Ce decreases the corrosion resistance of the alloy, which was highest with the addition of 0.4 wt% Ce. The Ecorr value is shifted in a positive direction, increasing from the standard electrode potential of Al (−1.66 V) to −0.997 V. In addition, the growth of tensile strength and yield strength becomes slow when the Ce addition exceeds 0.4 %. The results provide technical guidance for the development of new aluminum alloy materials with high corrosion resistance, high strength, and low cost.