A study of mechanical properties and microstructure in friction stir welded thin sheet aluminium alloys

Abstract

Friction stir welding of very thin aluminium sheets represents a potential goal for aircraft and automotive
industries due to the advantages of using this new technological process. In the present work, the
microstructural evolution and mechanical behaviour of 6082T6-2024T3 thin friction stir welded joints were
investigated. Uniaxial tensile testing at room temperature, 170°, 200° and 230°C were performed in order to
determine the extent to which these ultra thin joints can be used and deformed. The tensile stress-strain curves
showed a decrease of the flow stress with increasing temperature and decreasing strain rate.
At 230°C recovery mechanisms (dislocation reorganization inside the deformed grains) initiated but the
temperature was not enough high to produce a homogeneous subgrain structure.