Study on temperature distribution and residual stresses in friction stir welding of aluminium alloy AA2014

Abstract

Friction stir welding is a solid state welding process capable of joining high strength aluminium alloys that are difficult to be joined by fusion welding processes In FSW process heat is generated by friction between a rotating tool and the work piece Although FSW is a solid state process a significant magnitude of residual stress is present in the weld due to the complex fixturing system used during welding These residual stresses affect the properties of the welded components during their service Hence it becomes important to evaluate the nature of stresses developed during the FSW process For estimating the magnitude and distribution of welding residual stresses along with thermal cycles a three dimensional non linear thermo mechanical finite element model using ANSYS package was developed for butt welded aluminium alloy AA2014 T6 The variations in thermal and mechanical properties of the material with temperature were included in the model In the thermal modeling boundary conditions play a vital role in predicting the temperature profile In order to simulate the thermal fields during the FSW process the adaptive boundary conditions were used