Extensive analysis of the mechanical and microstructural properties of AA2024 alloy surface enhancement via friction stir processing

AA2024, a heat-treatable alloy with notable resistance to the plastic deformation, exhibits inadequate wear resistance. To overcome this deficiency, friction stir processing (FSP) was carried out at a rotational speed of 1000-1600 rpm, traverse speed of 15-45 mm/min, and axial load of 8-12.5 kN. The experiments were planned using the Box-Behnken Design method. A tool with a cylindrical pin was used. This research examines the impact of the process parameters on the mechanical characteristics of the AA2024 T351 alloy. The presence of precipitates in the processed zone has been identified. The microstructural growth of the FSPed samples at different locations can be recognized using the electron backscatter diffraction technique. The findings demonstrate that during FSP, the grains engage in dynamic recrystallization. The shear texture generated by FSP was evident in the pole figures. The deformation process translates a substantial portion of LAGBs sub-grains into HAGBs stability grains. The steady recrystallized grains with HAGBs and sub-grains with LAGBs influenced the mechanical characteristics. A reduction in the average grain size from 75.88 mu m to 37.97 mu m observed at the surface caused an increase in the hardness value of about 10.77%. The reduction in the grain size and precipitates owing to dynamic recrystallization and increased free energy manifested a 50.89% reduction in wear rate and 37.59% increased corrosion resistance.