Improved Accelerated Testing for Localized Corrosion Susceptibility of High-Strength Aluminum Alloys

Abstract:

Several accelerated tests for high-strength aluminum alloys, such as ASTM G34, ASTM G85 Annex 2, and ASTM G110 can produce significantly different results in third generation aluminum lithium (Al-Li) alloys. In this study, the reason for this inconsistency is investigated by comparing the electrochemical kinetics for AA2060 to those of AA2090 as well as legacy alloy AA7075-T6, and by comparing the performance of AA2060 in ASTM G110 and ASTM G85. The corrosion potential of AA2060 was found to be higher than that of AA7075-T6 and AA2060-T8E41. Also, it was found that although ASTM G110 does not produce exfoliation in AA 2060-T3 as in ASTM G85, the type of attack observed in cross-section is very similar in both tests.

• Periodical: Materials Science Forum (Volumes 794-796)
• Pages: 223-228
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.794-796.223
• Online since: June 2014
• Authors: Mary E. Parker*, Robert G. Kelly
• Keywords: Accelerated Testing, Aluminum Lithium, Exfoliation, Intergranular Corrosion (IGC)

References

[1] S. Lee, B.W. Lifka, Modification of the EXCO test method for exfoliation corrosion susceptibility in 7XXX, 2XXX and aluminum-lithium alloys, in: New Methods for Corrosion Testing of Aluminum Alloys, American Society for Testing and Material, Philadelphia, 1992, pp.1-19.

DOI: 10.1520/stp19577s

[2] J.P. Moran, F.S. Bovard, J.D. Chrzan, R.J. Rioja, E.L. Colvin, Improvements in corrosion resistance offered by newer generatiaon 2X99 aluminum-lithium alloys for aerospace applications, in: 12th International Conference on Aluminum Alloys, the Japan Institute of Metals, Yokohama, Japan, (2010).

DOI: 10.1002/9781118495292.ch62

[3] W.N. Garrard, Corrosion Behavior of Aluminum-Lithium Alloys, Corrosion, 50 (1994) 215 – 225.

DOI: 10.5006/1.3293513

[4] ASTM Standard G110 - 92, Standard practice for evaluating intergranular corrosion resistance of heat treatable aluminum alloys by immersion in sodium chloride + hydrogen peroxide solution, ASTM International, West Conshohocken, PA, (2003).

DOI: 10.1520/g0110

[5] R.J. Rioja, J. Liu, The evolution of Al-Li base products for aerosapce and space applications, Metall. Trans. A, 43A (2012) 3325-3337.

DOI: 10.1007/s11661-012-1155-z

[6] R. Ambat, E.S. Dwarakadasa, The Influence of pH on the corrosion of medium strength aerospace alloys 8090, 2091, and 2014, Corrosion Sci., 33 (1992) 681-690.

DOI: 10.1016/0010-938x(92)90102-9