Friction stir welding of AA7075-T6 alloy: influence of the operating parameters on weld quality, thermal field and microstructure
By Danilo Ambrosio (ENIT, LGP), Vincent Wagner (ENIT, LGP), Dimitri Jacquin (University of Bordeaux, I2M), Christian Garnier (ENIT, LGP), Amevi Tongne (ENIT, LGP), Marina Fazzini (ENIT, LGP), Olivier Cahuc (University of Bordeaux, I2M), Gilles Dessein (ENIT, LGP)

The present study provides a wide and detailed analysis on the impact of the operating parameters in FSW. Friction stir welding on AA6082-T6 plates varying axial force, rotational speed and welding speed have been performed. The correlation between operating parameters, weld quality, thermal history and microstructure is shown. The data and information gathered represent a useful insight to enrich the knowledge and to provide a better understanding of the process. A mapping of the welding parameters has been drawn up for two purposes. Firstly, for the influence on the occurrence of defects (e.g. worm hole, grooved surface, voids) and the temperature field. Secondly, for the morphology of welds (HAZ, TMAZ, Nugget) and the identification of the microstructure's genesis (precipitation and recrystallization cycles). Subsequently, the effect of the thermal field on the microstructure and weld quality has been investigated.