Temperature Distribution of Friction Stir Welded Al 7075 alloy using Finite Element Simulation along with Experimental Validation

Abstract

Finite element simulation (FE simulation) and experimental validation of Friction Stir Welding (FSW) has been performed on 3 mm thick plates of AA7075 at rotational speed 1000 rpm and transverse speed 50 mm/min. It is difficult to determine the temperature distribution of the workpiece and tool interface experimentally, wherein temperature distribution of workpiece is responsible for frictional heat generation. The frictional heat generation is one of the important factors affecting the material flow and joint quality of FSW. In present work, finite element simulation using Coupled Eulerian Lagrangian approach has been performed to estimate the temperature of the workpiece and the tool. The simulation result shows the temperature distribution of the workpiece and the tool. The maximum temperature was attained by the tool. The FE simulation predicts 308 C temperature adjacent to the shoulder which corresponds to experimentally measured temperature ∼ 290 C. The simulation predicts 531 C as the maximum temperature at the tool shoulder whereas the experimentally measured maximum temperature at the tool shoulder is found to be > 400 C, showing good agreement between simulation and experiment. The tensile strength 62.74 % of the base alloy and elongation of 11.5 % have been achieved in the experimentally produced FSW sample at 1000 rpm rotational speed and 50 mm/min transverse speed. The nugget zone of FSW has higher hardness due to the recrystallized fine grain and HAZ has comparatively lower hardness due to grain coarsening.