Salt fog corrosion behavior of friction stir welded AA2014-T651 aluminum alloy

Abstract

High strength aluminum alloys of type AA2014 are used in aerospace applications. This alloy is considered unweldable using fusion welding processes. Friction stir welding being a solid state process has been proved to be a suitable process for obtaining sound welds of these materials. In the current study, 8 mm thick rolled AA2014-T651 aluminum alloy plates were joined using friction stir welding. The corrosion behavior of base material and friction stir welds was investigated using the salt fog test (ASTM B117). The corrosion resistance of the welds and parent material in the basic solution was found to be better than that in acidic and neutral solutions. It was also found that the corrosion rate increases with increase in time of exposure. It has been observed that corrosion attack is greater in the weld region than in the parent material and within the weld, heat affected zone has been found to be more susceptible to corrosion compared to the weld nugget and thermomechanically affected zone regions. Transmission electron microscopy studies revealed coarser precipitates and precipitate-free zones in the heat affected zone which are concluded to be the reasons for more susceptibility to corrosion.

The Effect of High-Temperature Deformation on the Mechanical Properties and Corrosion Resistance of the 2024 Aluminum Alloy Joint after Friction Stir Welding

“…For example, Thamilarasan et al researched the salt fog corrosion behavior of friction-stir-welded AA2014-T651 aluminum alloy. The results showed that the corrosion resistance of the welds and parent material in the basic solution was better than that in acidic and neutral solutions [ 24 ]. Qin et al investigated the corrosion behavior of friction-stir-welded 2A14-T6 aluminum alloy in immersion exfoliation corrosion (EXCO) solution.…”

Investigation on corrosion behavior of cryogenically treated friction stir welded AA5083

“…Comprehensive re-views carried out by Mishra and Ma [3] and Nandan et al [4] revealed sizable amount of information on the effects of process parameters, variations in microstructures, and structure-property correlations. More recently, there have been a number of reports [5][6][7][8][9][10] highlighting the changes in microstructures, dissolution and coarsening of strengthening precipitates in the weld nugget and formation of wide precipitatefree zones in the heat affected zone due to the plastic defor-mation and frictional heat associated with FSW. Also, several investigators studied the corrosion behavior of friction stir welded aluminum alloys [11][12][13][14][15].…”