Microstructure and mechanical properties relation in cold rolled Al 2024 alloy determined by X-ray line profile analysis

Solution treated aluminum 2024 alloy sheets were subjected to rolling at room and cryogenic temperatures. Aging time and mechanical properties were evaluated by microhardness measurements and tensile test, respectively. Microstructural parameters were assessed by applying modified Williamson–Hall and modified Warren–Averbach methods to the X-ray diffraction patterns. Interestingly, the mechanical behavior of the different as-rolled and post-roll aged samples was in correlation with the sub-grain sizes and dislocation densities. The sub-grain sizes of the as-rolled samples were smaller than 40 nm, and the dislocation densities were larger than 7.7×1015 m−2, which is related to the high strength of the as-rolled samples. After aging treatment, the ductility of the rolled samples increased significantly, this was justified by the decline in the dislocation density.