STRUCTURAL CHARACTERIZATION OF WELDED AL6060-T5 ALLOY JOINTS BY FRICTION STIR SPOT WELDING UNDER CORROSION ATACK

Al6060-T5 alloys are widely used in the aerospace, shipbuilding and automotive industries. Nevertheless, the conventional welding process could be weakening its resistance to corrosion. Thus, Friction Stir Spot Welding (FSSW) becomes an alternative to reduce the thermally affected zone (HAZ) at the joints. Although, persist a lack of studies, on current literature, about these welding properties; as welds its corrosion resistance. With this in mind, this present paper evaluated an Al6060-T5 alloy plates welds after periods of 336, 672 and 1008 hours into 3.5% NaCl electrolyte immersion. Where, for each period, the plates were evaluated in terms of open circuit potentials (OCP), micro hardness Vickers, elemental composition and its corrosion severity. The results shown a percentage increasing of oxygen rate (3 to 4%); identifying corrosive activity in the mixing zone. Likewise, electrochemical tests shown a greater susceptibility to corrosion at weld nearing centre regions; due to Mg and Si precipitates presence. Even so, all immersion times samples presented a mild corrosive severity