Corrosion resistance of a two-stage stress-aged Al-Cu-Mg alloy: Effects of stress-aging temperature

摘要

Two-stage stress-aging experiments of an Al-Cu-Mg alloy were performed. The effects of stress-aging temperature on corrosion resistance of the two-stage stress-aged Al-Cu-Mg alloy are discussed. It is found that the stress-aging temperature significantly affects corrosion resistance, which is ascribed to the evolution of aging precipitates. The aging precipitates uniformly nucleate in the first stage of two-stage stress-aging. Increasing stress-aging temperature can enhance the uniform distribution of precipitates, but precipitates easily become coarse in the second stage of two-stage stress-aging. The coarsen precipitates enlarge the potential difference between aging precipitate and aluminum matrix, and decrease the corrosion resistance. So, the corrosion resistance of the stress-aged alloy decreases with the increase of the second stage stress-aging temperature. Furthermore, the optimized stress-aging temperature is about 433 K within the tested conditions. (C) 2015 Elsevier B.V. All rights reserved.