| Description |
Aluminum magnesium alloys, due to their high strength and overall corrosion resistance, are used more and more in a variety of applications, from automobiles to navy ships. The addition of magnesium greatly increases the strength of aluminum. However, at elevated temperatures beta phase particles (Al2Mg3) can precipitate along grain boundaries and lead to intergranualar corrosion and stress corrosion cracking. The corrosion of these alloys has been widely studied and the ASTM G67 standard mass loss test is used to compare the degree to which the alloy has been sensitized by the formation of beta phase particles. A simple model was developed, based on the ASTM G67 test, in order to predict the mass loss of an aluminum alloy, given several key parameters, such as beta phase thickness and continuity of the beta phase along the grain boundary. The model was validated through SEM, TEM, and AFM imaging. This mass loss model was combined with previous work, which estimates key parameters, creating a predictive tool to allow for useful projections of service life in 5xxx aluminum alloys. |
