Aging and Mechanical Behavior of Be-Treated 7075 Aluminum Alloys

Authors: Mahmoud M. Tash, S. Alkahtani

Abstract:

The present study was undertaken to investigate the effect of pre-aging and aging parameters (time and temperature) on the mechanical properties of Al-Mg-Zn (7075) alloys. Ultimate tensile strength, 0.5% offset yield strength and % elongation measurements were carried out on specimens prepared from cast and heat treated 7075 alloys. Aging treatments were carried out for the as solution treated (SHT) specimens (after quenching in warm water). The specimens were aged at different conditions; Natural aging was carried out at room temperature for different periods of time. Double aging was performed for SHT conditions (pre-aged at different time and temperature followed by high temperature aging). Ultimate tensile strength, yield strength and % elongation as a function of different pre-aging and aging parameters are analyzed to acquire an understanding of the effects of these variables and their interactions on the mechanical properties of Be-treated 7075 alloys.

Keywords: Duplex Aging Treatment, Mechanical Properties, Al-Mg-Zn (7075) alloys.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1099236

References:

[1] I.J. Polmear, “Recent Developments in Light Alloys,” Materials Transactions, JIM, 37(1) (1996), 12-31.
[2] H.Y. Hunsicker, “Development of Al-Zn-Mg-Cu Alloys for Aircraft,” Proceeding Rosenhain Century Conference, Metals Society, London, (1976), 359-376.
[3] J.T. Staley, “History of Wrought-Aluminium-Alloy Development,” Aluminium Alloys: Contemporary Research and Applications, Treaties on Materials Science andTechnology, Academic Press, 31 (1989), 3-31.
[4] Patent No. EP0377779B2, “Aluminum Alloy Product Having Improved Combinations of Strength, toughness and Corrosion Resistance,” New European Patent Specification, Bulletin 2001/36, 5 September 2001.
[5] N.E. Paton and A.W. Sommer, “Influence of Thermomechanical Processing Treatments on Properties of Aluminum Alloys,” Proceeding Third international Conference onStrength of Metals and Alloys, Metals Society, London, 1 (1973), 101-108.
[6] A. Yamamoto et al., “Calorimetric and Resistivity Study of formation and Redissolution of Precipitates in 7050 Aluminum Alloy,” Materials Transactions, JIM, 39 (1) (1998), 69-74.
[7] A. Joshi, C.R. Shastry and M. Levy, “Effect of Heat Treatment on Solute Concentration at Grain Boundaries in 7075 Aluminum Alloy,” Metallurgical Transactions A, 12 (A) (1981), 1081-1088.
[8] M.E. Fine, “Precipitation Hardening of Aluminum Alloys,” MetallurgicalTransactionsA, 6 (A) (1975), 625-630.
[9] J.K. Park and A.J. Ardell, “Microstructures of the Commercial 7075 Al Alloy in the T651 and T7 Tempers,” Metallurgical Transactions A, 14 (A) (1983), 1957-1965.
[10] A. Karaaslan, I. Kaya and H. Atapek, “Effect of Aging Temperature and of Retrogression Treatment Time on the Microstructure and Mechanical Properties of Alloy AA 7075,” Metal Science and Heat Treatment, 49 (9-10) (2007), 443-447.
[11] J.K. Park and A.J. Ardell, “Effect of Retrogression and Reaging treatments on the Microstucture of Al-7075-T651,” Metallurgical Transactions A, 15 (A) (1984), 1531- 1543.
[12] S.V. Emani et al., “Double Aging and Thermomechanical Heat Treatment of AA 7075 Aluminum.
[13] A. H. Geisler; “Phase Transformation in Solids”, Willey, New York, 1951, p.387.