On the role of texture in governing fatigue crack propagation behavior of 2524 aluminum alloy

The texture evolution of AA2524 cold-rolled sheet during annealing process and texture effect on fatigue crack propagation (FCP) behavior were investigated. Results showed the sample annealed at 400 °C for 45 min and solid solution-treated at 490 °C for 20 min had the strongest Goss and P textures, and possessed the lowest FCP rates. EBSD examination indicated Goss, P, Q, Cube, R and S grains induced great crack deflection to retard crack growth, when having large twist and tilt angle component boundary or pure twist boundary with neighboring grains. In the case of small angle boundary or relatively large angle tilt boundary with adjacent grains, Cube, Copper and R grains induced little crack deflection. Additionally, SEM results showed, in the presence of large twist angle component boundary or pure twist boundary, more severely plastic deformation presenting numerous slip bands occurred in Cube, R and S grains than that in Goss, P and Q grains during crack propagation. In contrast, no evident slip bands formed in Cube, Copper and R grains when having small angle boundaries or relatively large tilt angle boundary.