Numerical simulation and experimental investigation of friction stir lap welding between aluminum alloys AA2024 and AA7075

A Computational Fluid Dynamics (CFD) based modified three-dimensional model was developed to predict the distribution of temperature during lap friction stir welding (FSW) of dissimilar aluminum alloys AA2024 and AA7075. Volume of fluid approach was used and the lap FSW process was modeled as a steady-state visco-plastic turbulent flow past a rotating tool. The experimental records of transient temperature at several specific locations were used for checking the temperature field gained by numerical simulation. The temperature distribution, variations in temperature and thermal history of the processed zone were investigated. Results indicate that there is an obvious asymmetric temperature distribution between the advancing side (AS) and the retreating side (RS). The temperature distribution and variation of each observation point was different. The temperature of the observation points rose rapidly but decreased slowly. In particular, the temperature distribution was not continuous due to the difference of the material properties, and the temperature changes had saltation at the interface of upper and lower plates. (C) 2016 Elsevier B.V. All rights reserved.