Tribocorrosion of friction-stir-welded Ti6AL4V in 3.5% NaCl aqueous solution

Ti6Al4V has extensive uses in the marine and biomedical industry. In some of these applications, corrosion is present with additional mechanical wear. Thus, the corrosion, wear and their synergistic properties were investigated in applications where there were specifically induced material property changes, such as in welding. One such welding technique, friction-stir-welding, is a well-suited method for joining plates of the Ti6Al4V alloy. The purpose of the work was to investigate the effect of mechanical wear combined with electrochemical corrosion on the various weld zones of the material in a salt solution. The corrosive properties of the advancing side, retreating side and weld-zone regions of the material were compared to the properties of the parent material. The study showed that, when compared to the parent material, heat-affected zone and the weld zone, the advancing side was found to possess lower wear corrosion properties when compared to the retreating side. In addition, the weld zone was shown to have the lowest material loss per year under tribocorrosion conditions.