Microstructure and Its Effect on the Intergranular Corrosion Properties of 2024-T3 Aluminum Alloy

Intergranular corrosion is the main type of Al-Cu-Mg aluminum alloys, which seriously reduce lifetime aircraft structural parts. In this paper, microstructure and intergranular behavior 2024 alloy with varying Cu Mg content were studied by using a scanning electron microscope (SEM), transmission (TEM), three-dimensional atom probe (3DAP). The results show that nano-scale θ (Al2Cu) S (Al2CuMg) particles precipitate along grain boundaries after quenching. nano-cluster strengthening phase in natural aging for 96 h. susceptibility greatly affected presence phases boundaries. Specifically, Cu-rich precipitates intermetallics are known to act as local cathodes, facilitates action oxygen reduction ultimately drives anodic dissolution surrounding matrix material. resistance decreases increase contents. lower shows better than commonly used one mass ratio 2.9. relationship between observed various contents elements discussed, has potential benefit composition design 2xxx high resistance.