Precipitation microstructures in an AA6056 aluminium alloy after friction stir welding: Characterisation and modelling

The effect of friction stir welding on the microstructure and local properties of the AA6056 alloy has been investigated for both T4 and T78 initial states. A particular attention was devoted to the relationship between the fine hardening precipitation within the affected zones and local hardness. In the heat-affected zones of the T4 weld an extensive heterogeneous precipitation is occurring on dislocations and dispersoids whereas the …