Effect of Exfoliation Corrosion on the Mechanical Properties of Friction Stir Spot Welded 2024-T3 AA Joints

Abstract

This study aims to detect the impact of preexfoliation corrosion on the efficiency of 2 mm thick 2024-T3 aluminum alloy friction stir spot welded (FSSW) joints. Five specimens of FSSW joints, welded with 620 r·min−1 rotational speed and a dwell time of 10 seconds, were immersed in an exfoliation corrosion solution for five different times: 10 h, 20 h, 30 h, 40 h, and 50 h. The tensile shear load for the noncorroded joint was 3.5 kN. The results showed that the degradation of mechanical properties increased with increasing exposure time, and the joint efficiency drop reached 62% for specimens exposed for 50 h to the corroded solution. As welded FSSW 2024-T3 AA joints exhibited a nugget debonding failure mode and a mixed-mode tensile-shear fracture, in the corroded specimens, only a shear fracture could be seen. The results were attributed to a reduction in the bonding area between the upper and lower sheets due to corrosion.

Influence of the Friction Stir Process on the Corrosion Resistance, Machining, and Mechanical Properties of Al6101-SiC Composite

“…Friction stir processing is the extension solid-state procedure of friction stir welding (FSW) to change the microstructure of the surface. In-depth explanations of grain refning and material fow mechanisms during FSW and FSP can be found elsewhere [2,3]. Certain material properties of the composites are infuenced by microstructure alteration and the incorporation of other metals in the form of surface reinforcement by friction stir process [4][5][6].…”