Thermal Mapping of the Friction Stir Welding Process

Friction Stir Welding is a solid state ‘green’ welding method developed by The Welding Institute (UK). An internal thermal mapping instrument has been developed which allows for symmetrical mapping of the thermal fields developed by a Friction Stir Welding tool as it passes through the material being welded. This symmetrical mapping conclusively documents statistically the asymmetrical nature of the heat sources within the friction stir welding process. The various models in the literature are compared against these results. A model developed by the authors using classic metal cutting theory predicts the observed thermal fields. A successful predictive model will facilitate tool optimization and welding schedules, while optimizing the mechanical properties of the weld.