Study of friction stir spot welding on AA6063 aluminium alloy used in the ship building industry

ABSTRACT Friction stir spot welding (FSSW) is a novel process of metal joining. In the present work, the authors analysed the possibility of using this process to solve current problems in shipbuilding industry regarding small vessels by replacing the current arc welding techniques with the aforementioned process. Numerical simulation was carried out by the multiple purpose solver framework for Finite Element Method with a novel modelling approach. The problem was solved using a coupled mechanics system of equations in an axisymmetric continuum where material velocities were calculated in three dimensions, coupled with pressure and thermal fields. The heat source was calculated as a consequence of internal friction dissipation only. Two boundary conditions were analysed, adiabatic and with heat dissipation. Experimental welding tests were performed using a milling machine. Comparison between numerical modelling results and experimental FSSW testing results was done and analysed in detail.