Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 53 6 2021 08 23 Numerical investigation and prediction of grain size in different friction stir welding areas of AA6061 aluminum alloy Numerical investigation and prediction of grain size in different friction stir welding areas of AA6061 aluminum alloy 3751 3760 4192 10.22060/mej.2020.18746.6881 FA Amir Ghiasvand Tabriz university Mahdi Kazemi Maziar Mahdipour Jalilian Mechanical Engineering Department, Kermanshah Branch, Islamic Azad University, Kermanshah, Iran Journal Article 2020 07 18 Friction stir welding is a solid-state bonding technique based on two factors, a pressure greater than the material yield stress and large plastic deformation. The final joint between parts takes place in different welding geometries by using these two factors. The grain sizes in the weld areas are influenced by recovery, recrystallization, and grain growth. In the current research, using an analytical-numerical method based on finite element simulation of friction stir welding of AA6061-T6 alloy, the grain sizes in various welded areas have been predicted. The finite element simulation has been performed based on the coupled Eulerian-Lagrangian approach using ABAQUS software and the results have been verified by experiments. The predicted results were in good agreement with the experimental results. Due to the concentration of heat and plastic flow in the central region of the weld, the stirring region had the most microstructural changes and the grain size in this region decreased more sharply than other different areas of the weld. As the rotational welding speed increases, recrystallization phenomena in the central weld area increases. With increasing the translational welding speed, grain size increased in different welding areas. This increase occurred more severely in the central area of the welded joint. Friction stir welding is a solid-state bonding technique based on two factors, a pressure greater than the material yield stress and large plastic deformation. The final joint between parts takes place in different welding geometries by using these two factors. The grain sizes in the weld areas are influenced by recovery, recrystallization, and grain growth. In the current research, using an analytical-numerical method based on finite element simulation of friction stir welding of AA6061-T6 alloy, the grain sizes in various welded areas have been predicted. The finite element simulation has been performed based on the coupled Eulerian-Lagrangian approach using ABAQUS software and the results have been verified by experiments. The predicted results were in good agreement with the experimental results. Due to the concentration of heat and plastic flow in the central region of the weld, the stirring region had the most microstructural changes and the grain size in this region decreased more sharply than other different areas of the weld. As the rotational welding speed increases, recrystallization phenomena in the central weld area increases. With increasing the translational welding speed, grain size increased in different welding areas. This increase occurred more severely in the central area of the welded joint. https://mej.aut.ac.ir/article_4192_cd474f6341aeffd65f93084d0dae3453.pdf