Investigating and Rationalizing Influence of Saline Environment on Response of an Aluminum Alloy: Experimental and Numerical Study

A sizeable number of structures, as key load-bearing components, are currently being made using both high-strength and medium-strength alloys of aluminum. During their service life, these alloys are often exposed to environments spanning a range of aggressiveness. In this study, the corrosion behavior of a high-strength aluminum alloy in both static and flowing saline solution was conducted using both experimental and numerical analysis. The damage resulting from environment-induced degradation, or corrosion, of the test specimens upon exposure to flowing saline solution was noticeably severe in comparison with the damage caused by exposure to static saline solution. Subsequent to flow-induced degradation, an analysis of dispersion of the corrosion products over the surface revealed it to be in the direction of flowing saline solution. The higher the flow rate of saline solution over the sample surface, the more severe and visibly evident was the severity of damage due to environment-induced degradation. Microscopic observations of the corrosion morphology for the three different flow rates revealed a greater degree of damage to the surface with an increase in flow rate of the saline solution. This can be quantified by both an increase in area of the sample that is degraded and depth of the corrosion-induced pits. Using cellular automata algorithm in conjunction with matlab software, the damage caused by flowing saline solution for three different flow rates predicted fairly accurately the severity of the environment-induced damage due to corrosion and resultant morphology of the corrosion-related debris.