Fatigue Characteristic Analysis of New ECO7175v1 Extruded Aluminum Alloy
Publication: Journal of Aerospace Engineering
Volume 32, Issue 1
Abstract
This paper investigates the fatigue characteristics of a new extruded aluminum 7175, with an experimental composition which uses a magnesium-calcium alloy during the alloying process instead of the standard pure magnesium. This new aluminum 7175, dubbed aluminum ECO7175v1, results in a cleaner manufacturing process and improves mechanical properties. The fatigue behavior of the new aluminum ECO7175v1 T74 temper is investigated. Experimental data show that the fatigue life of ECO7175v1-T74 aluminum can exceed cycles with a fatigue strength of approximately 207 MPa, about 36% of its tensile strength. Fractography results show that failure modes are predominately ductile near the surface and brittle toward the center. In addition, at higher stresses, crack initiation points are typically at the surface of the specimens, compared with those at lower stresses. Irrespective of the stresses to which the specimens are subjected, all crack initiation points are located at the surface and no inclusions to act as stress concentrators are seen.
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References
Aluminum Association. 2015. International alloy designations and chemical composition limits for wrought aluminum and wrought aluminum alloys. Arlington, VA: Aluminum Association.
Battelle Memorial Institute. 2016. Metallic materials properties development and standardization (MMPDS). Columbus, OH: Battelle Memorial Institute.
Davis, J. R. 1993. ASM specialty handbook: Aluminum and aluminum alloys. Materials Park, OH: ASM International.
Kaufman, G. J. 2000. Introduction to aluminum alloys and tempers. Materials Park, OH: ASM International.
Kim, S. H., K. S. Kim, S. K. Kim, Y. O. Yoon, K. S. Cho, and K. A. Lee. 2012. “Microstructure and mechanical properties of Eco-2024-T3 aluminum alloy.” Adv. Mater. Res. 602–604: 623–626. https://doi.org/10.4028/www.scientific.net/AMR.602-604.623.
Kim, S. K., and J.-K. Lee. 2011. “Effect of CaO addition on the ignition resistance of Mg-Al alloys.” Mater. Trans. 52 (7): 1483–1488. https://doi.org/10.2320/matertrans.M2010397.
Kim, S. K., J.-K. Lee, Y.-O. Yoon, and H.-H. Jo. 2006. “Green manufacturing for magnesium alloys.” In Proc., World Foundry Congress, 1–34. West Midlands, UK: Institute of Cast Metals Engineers.
Lim, J.-K., S.-J. Hwang, O.-Y. Lee, I.-S. Eun, and D.-S. Shin. 1996. “Fatigue crack growth behavior for 7000 series high strength Al alloys on strengthening heat treatment.” In Proc., 6th Int. Fatigue Conf., edited by G. Lütjering and H. Nowack, 947–952. Berlin: Pergamon.
Lim, S. T., I. S. Eun, and S. W. Nam. 2003. “Control of equilibrium phases (M,T,S) in the modified aluminum alloy 7175.” Mater. Trans. 44 (1): 181–187. https://doi.org/10.2320/matertrans.44.181.
Lipson, C., and N. J. Sheth. 1973. Statistical design and analysis of engineering experiments. New York: McGraw-Hill.
Mayer, H., W. Haydn, R. Schuller, S. Issler, B. Furtner, and M. Bacher-Höchst. 2009. “Very high cycle fatigue properties of bainitic high carbon–chromium steel.” 31 (2): 242–249. https://doi.org/10.1016/j.ijfatigue.2008.09.001.
Nam, T. H., S. H. Kim, J. G. Kim, and S. K. Kim. 2014. “Corrosion resistance of extruded Mg–3Al–1Zn alloy manufactured by adding CaO for the replacement of the protective gases.” Mater. Corros. 65 (6): 577–581. https://doi.org/10.1002/maco.201206849.
Ochi, Y., T. Matsumura, K. Masaki, and S. Yoshida. 2002. “High-cycle rotating bending fatigue property in very long-life regime of high-strength steels.” Fatigue Fract. Eng. Mater. Struct. 25 (8–9): 823–830. https://doi.org/10.1046/j.1460-2695.2002.00575.
Shiozawa, K., L. Lu, and S. Ishihara. 2001. “S–N curve characteristics and subsurface crack initiation behaviour in ultra-long life fatigue of a high carbon-chromium bearing steel.” Fatigue Fract. Eng. Mater. Struct. 24 (12): 781–790. https://doi.org/10.1046/j.1460-2695.2001.00459.
Wang, Q. Y., N. Kawagoishi, and Q. Chen. 2006. “Fatigue and fracture behaviour of structural Al-alloys up to very long life regimes.” Int. J. Fatigue 28 (11): 1572–1576. https://doi.org/10.1016/j.ijfatigue.2005.09.017.
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©2018 American Society of Civil Engineers.
History
Received: Mar 9, 2018
Accepted: Jun 22, 2018
Published online: Oct 27, 2018
Published in print: Jan 1, 2019
Discussion open until: Mar 27, 2019
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