A Numerical and Experimental Analysis of Microstructural Aspects in AA2024-T3 Friction Stir Welding

Heat generation and material stirring in friction stir welding induce significant microstructural alteration in the base material. The influence of microstructural aspects on mechanical properties and formability of FSWed assemblies is well recognized in the recent literature. In this paper the influence of process parameters, namely rotating speed and welding speed, on microstructural aspects in AA2024-T3 friction stir butt welds is numerically and experimentally investigated. A three-dimensional CFD model has been implemented to simulate temperature field, material flow, and microstructural aspects in an Eulerian framework. Recrystallized grain size has been numerically predicted taking into account the Zener-Holloman parameter and experimentally measured by means of conventional metallographic techniques. Satisfactory agreement has been found between simulated and experimental results.