Effect of aging temperature on intergranular corrosion susceptibility of 7055 aluminum alloy

doi:10.13251/j.issn.0254-6051.2025.01.032

Abstract

Abstract: Effect of aging temperature (150, 180, 210 ℃) on intergranular corrosion susceptibility of 7055 aluminum alloy was studied by means of optical microscope (OM), transmission electron microscope(TEM), hardness test and intergranular corrosion test. The results show that under the same hardness condition, intergranular corrosion occurs in the under-aged alloy, while pitting corrosion occurs in the peak-aged and over-aged alloys. With the increase of aging temperature and time, the intergranular corrosion susceptibility of the alloy decreases and the corrosion morphology changes from intergranular corrosion to pitting corrosion. With the aging temperature increasing from 150 ℃ to 210 ℃, the grain boundary precipitates (GBPs) change from continuous distribution to discontinuous distribution, the Cu content in GBPs increases from 3.82% to 5.02%, and the width of precipitate free zones (PFZs) increases from 37 nm to 55 nm. The change of intergranular corrosion susceptibility of the alloy is due to the combined effect of coarsening and discontinuous distribution of GBPs, the broadening of PFZs, and the segregation of Cu element in GBPs.

Key words: 7055 aluminum alloy, aging temperature, microstructure, intergranular corrosion susceptibility

CLC Number:

TG146.21

Zhu Cong, Wang Zhixiu, Wang Ye, Li Hai. Effect of aging temperature on intergranular corrosion susceptibility of 7055 aluminum alloy[J]. Heat Treatment of Metals, 2025, 50(1): 206-212.

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