Effect of Localized Corrosion on Fatigue–Crack Growth in 2524-T3 and 2198-T851 Aluminum Alloys Used as Aircraft Materials
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Corrosion and fatigue of aluminum alloys are major issues for the in-service life assessment of aircraft structures and for the management of aging air fleets. The aim of this work was to evaluate the effect of localized corrosion on fatigue crack growth (FCG) resistance of the AA2198-T851 Al-Li alloy (Solution Heat Treated, Cold Worked, and Artificially Aged), comparing it with the FCG resistance of AA2524-T3 (Solution Heat Treated and Cold Worked), considering the effect of seawater fog environment. Before fatigue tests, the corrosion behavior of 2198-T851 and 2524-T3 aluminum alloys was verified using open circuit potential and potentiodynamic polarization techniques. Fatigue in air and corrosion fatigue tests were performed applying a stress ratio (R) of 0.1, 15 Hz (air) and 0.1 Hz (seawater fog) frequencies, using a sinusoidal waveform in all cases. The results showed that the localized characteristics of the 2198-T851 and 2524-T3 aluminum alloys are essentially related to the existence of intermetallic compounds, which, due to their different nature, may be cathodic or anodic in relation to the aluminum matrix. The corrosive medium has affected the FCG rate of both aluminum alloys, in a quite similar way.
KeywordsAl alloys corrosion–fatigue seawater fog environment 2XXX series Al alloys
The authors gratefully acknowledge the Department of Materials Engineering, University of São Paulo—USP for providing the laboratory facilities and the Brazilian research funding agencies CNPq (Processes: 303684/2015-1 and 402142/2016-0) and CAPES (Process: BEX4936/10-8) for their financial support.
The authors would like to express their thanks to Professor Fernando Quites, in memorian, for the contributions made in this work.
- 1.G.E. Totten and D.S. Mackenzie, Handbook of Physical Metallurgy and Process, CRC Press, New York, 2003Google Scholar
- 3.ASM International, ASM SPECIALTY Handbook: Aluminum and Aluminum Alloys in Aluminum-Lithium Alloys, Ohio, ASM International, 1993, p 121Google Scholar
- 4.B. Decreus, A. Deschams, P. Donnadieu, in Understanding the Mechanical Properties of 2198 Al-Li-Cu Alloy in Relation with the Intra-Granular and Inter-Granular Precipitate Microstructure. International Conference on the Strength of Materials. (Book Series: Journal of Physics Conference Series, v.240, Aug. 2009, 2009).Google Scholar
- 8.T.L. Anderson, Fracture Mechanics Fundamentals and Applications, 2nd ed., CRC Press, Boca Raton, 1995Google Scholar
- 9.American Society for Metals, Metals Handbook, 9th ed., ASM International, Ohio, 1990Google Scholar
- 11.American Society for Testing and Materials, ASTM E8 M: Standard Test Methods for Tension Testing of Metallic Materials, American Society for Testing and Materials, Philadelphia, 2000Google Scholar
- 12.American Society for Testing and Materials, ASTM E647: Standard Test Method for Measurement of Fatigue Crack Growth Rates, American Society for Testing and Materials, Philadelphia, 2008Google Scholar
- 13.ASTM, ASTM B909-00: Standard Guide for Plane Strain Fracture Toughness Testing of Non-stress Relieved Aluminum Products, Annual Book Of Standards, Section 2—Nonferrous Metal Products, vol. 02.02, Aluminum and Magnesium Alloys, ASTM, West Conshohocken, 2001, p 614–617Google Scholar
- 14.S.J. Hudak, Jr., A. Saxena, R.J. Bucci, and R.C. Malcolm, Development of Standard Methods of Testing and Analyzing Fatigue Crack Growth Rate Data—Final Report, AFML TR 78-40, Air Force Materials Laboratory, Wright Patterson Air Force Base, Dayton, 1978Google Scholar
- 15.P. Cavaliere and A. Santis, Effect of Anisotropy on Fatigue Properties of AA2198 Al-Li Plates Joined by Friction Stir Welding, Metall. Sci. Technol., 2008, 26(2), p 21–130Google Scholar
- 16.R.C. Souza, in Efeito do estiramento no comportamento em fadiga da liga de Al 2524-T3. Congresso Brasileiro de Ciência e Engenharia de Materiais (IPEN, Foz do Iguaçu, 2006).Google Scholar
- 17.R.P. Wei, R.P. Gangloff, in Fracture Mechanisms: Perspectives and Directions (Twentieth Symposium), ASTM STP 1020, ed. by R. P Wei, R. P Gangloff (American Society for Testing Materials, Philadelphia, 1989), pp. 233–264.Google Scholar
- 18.S. Suresh, Fatigue of Materials, Cambridge University Press, Cambridge, 1991Google Scholar
- 19.N.E. Dowling, Mechanical Behavior of Materials, Prentice Hall Inc., Englewood Cliffs, 1993Google Scholar
- 21.A. Tzamtzis and A.T. Kermanidis, Improvement of Fatigue Crack Growth Resistance by Controlled Over Aging in 2024-T3 Aluminium Alloy, Fatigue Fract. Eng. Mater. Struct., 2014, 00, p 1–13Google Scholar
- 25.J.A. Moreto. (2012) Estudo da corrosão e corrosão-fadiga em ligas de Al e Al - Li de alta resistência para aplicação aeronáutica. Tese (Doutorado em Ciência e Engenharia de Materiais) - Ciência e Engenharia de Materiais, Universidade de São Paulo, São Carlos, 2012.Google Scholar
- 26.S.C. Ferreira, L.A. Rocha, E. Ariza, P.D. Sequeira, Y. Watanabe, and J.C.S. Fernandes, Corrosion Behaviour of Al/Al3Ti and Al/Al3Zr Functionally Graded Materials Produced by Centrifugal Solid-Particle Method: Influence of the Intermetallics Volume fraction, Corros. Sci., 2011, 53, p 2058–2065CrossRefGoogle Scholar
- 30.J. Xiong, M. Liu, Modelling Crack Propagation in Aluminium-Alloys 2524-T3 and 7050-T7452 Subjected to Fatigue Loading at Low Temperature. Preprints 2016, 2016100066.Google Scholar