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The effect of pre-ageing on the microstructure and properties of 7050 alloy

Published online by Cambridge University Press:  22 December 2015

Yuan Liu*
School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, Heilongjiang Province, China
Wenjun Li
School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, Heilongjiang Province, China
Daming Jiang
School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, Heilongjiang Province, China
a)Address all correspondence to this author. e-mail:
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In the present work, the effect of pre-ageing temperature and time variations on the mechanical properties and electrical conductivity of the Retrogression and re-aging (RRA) treated 7050 has been investigated. The results reveal that the electronic conductivity and hardness of RRA-treated samples are sensitive to the pre-ageing tempers. The RRA-treated samples with 120 °C/2 h pre-ageing +180 °C/2 h retrogression +120 °C/24 h re-ageing temper can be tailored toward a good combination of strength and elongation, while the electrical conductivity of re-ageing samples is also higher than that of 120 °C/24 h pre-ageing RRA-treated samples. With an intermediate pre-ageing temperature of 80 °C/24 h RRA-treated samples possess a higher re-aged electronic conductivity, while no significant differences can be found between hardness of 120 °C/2 h and 120 °C/24 h pre-ageing RRA-treated samples. The variation of hardness and electronic conductivity during retrogression depends on the pre-ageing tempers. For under-aged sample, the retrogression hardness appears a stage of hardness increasing followed by a further decrease in hardness results, owing to disappearance of dissolving stage of fine GP zone and η′ phase during pre-ageing.

Copyright © Materials Research Society 2015 

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Contributing Editor: Yang-T. Cheng



Zhao, Y.H., Liao, X.Z., and Zhu, Y.T.: Enhanced mechanical properties in ultrafine grained 7075 Al alloy. J. Mater. Res. 20, 288 (2005).Google Scholar
Vojtech, D. and Tagiev, E.: Casting properties of the high-strength AlZnMgCuNiSi alloys. J. Mater. Res. 18, 635 (2003).CrossRefGoogle Scholar
Immarigon, J.P., Holt, R.T., Koul, A.K., Zhao, L., Wallace, W., and Beddoes, J.C.: Lightweight materials for aircraft applications. Mater. Charact. 35, 41 (1995).Google Scholar
Williams, J.C. and Starke, E.A.: Progress in structural materials for aerospace systems. Acta Mater. 51, 5775 (2003).CrossRefGoogle Scholar
Heinz, A., Haszler, A., Keidel, C., Moldenhauer, S., Benedictus, R., and Miller, W.S.: Recent development in aluminum alloys for aerospace applications. Mater. Sci. Eng., A 280, 102 (2000).Google Scholar
Miller, W.S., Zhuang, L., Bottema, J., Wittebrood, A.J., De Smet, P., Haszler, A., and Vieregge, A.: Recent development in aluminium alloys for the automotive industry. Mater. Sci. Eng., A 280, 37 (2000).Google Scholar
Liu, B., Peng, C.Q., Wang, R.C., Wang, X.F., and Li, T.T.: Recent development and prospects for giant plane aluminum alloys. Trans. Nonferrous Met. Soc. China 20, 1705 (2010).Google Scholar
Liu, Y., Jiang, D.M., Li, B.Q., Yang, W.S., and Hu, J.: Effect of cooling aging on microstructure and mechanical properties of an Al-Zn-Mg-Cu alloy. Mater. Des. 54, 79 (2014).CrossRefGoogle Scholar
Xu, L., Dai, G.Z., Huang, X.M., Zhao, J.W., Han, J., and Gao, J.W.: Foundation and application of Al–Zn–Mg–Cu alloy flow stress constitutive equation in friction screw press die forging. Mater. Des. 47, 465 (2013).Google Scholar
Sharma, C., Dwivedi, D.K., and Kumar, P.: Effect of post weld heat treatments on microstructure and mechanical properties of friction stir welded joints of Al–Zn–Mg alloy AA7039. Mater. Des. 43, 134 (2013).Google Scholar
Li, J., Li, F., He, M., Xue, F., Zhang, M., and Wang, C.: Indentation technique for estimating the fracture toughness of 7050 aluminum alloy with the Berkovich indenter. Mater. Des. 40, 176 (2012).Google Scholar
Oliveira, A.F., Barros, M.C., Cardoso, K.R., and Travessa, D.N.: The effect of RRA on the strength and SCC resistance on AA7050 and AA7150 aluminum alloys. Mater. Sci. Eng., A 379, 321 (2004).Google Scholar
Parker, J.K. and Ardell, A.J.: Effect of retrogression and re-aging treatments on the microstructure of A1-7075-T651. Metall. Trans. 15, 1531 (1984).Google Scholar
Viana, F., Pinto, A.M.P., Santos, H.M.C., and Lopes, A.B.: Retrogression and re-ageing of 7075 aluminium alloy: Microstructural characterization. J. Mater. Process. Technol. 93, 54 (1999).Google Scholar
Cina, B. and Talianke, M.: Retrogression and reaging and the role of dislocations in the stress corrosion of 7000-type aluminum alloys. Metall. Trans. A 20, 87 (1989).Google Scholar
Wu, X.J., Raizenne, M.D., Chen, W.R., Poon, C., and Wallace, W.: Thirty years of retrogression and re-aging. In Brescia, Italy: In ICAS 2002 Congress (pp. 1–11).Google Scholar
Ural, K.: A study of optimization of heat-treatment conditions in retrogression and reaging treatment of 7075-T6 aluminum alloy. J. Mater. Sci. Lett. 13, 383 (1994).CrossRefGoogle Scholar
Li, J.F., Birbilis, N., Li, C.X., Jia, Z.Q., Cai, B., and Zheng, Z.Q.: Influence of retrogression temperature and time on the mechanical properties and exfoliation corrosion behavior of aluminium alloy AA7150. Mater. Charact. 60, 1334 (2009).Google Scholar
Xiao, Y.P., Pan, Q.L., Li, W.B., Liu, X.Y., and He, Y.B.. Influence of retrogression and re-aging treatment on corrosion behavior of an Al–Zn–Mg–Cu alloy. Mater. Des. 23, 2149 (2011).CrossRefGoogle Scholar
Puiggali, M., Zielinski, A., Olive, J.M., Renauld, E., Desjardins, D., and Cid, M.: Effect of microstructure on stress corrosion cracking of an Al-Zn-Mg-Cu Alloy. Corrs. Sci. 40, 805 (1998).Google Scholar
Meng, G.J. and Frankel, G.S.: Effect of Cu content on corrosion behavior of 7xxx series aluminum alloys. J. Electrochem. Soc. 151, 271 (2004).CrossRefGoogle Scholar
Marlaud, T., Deschamps, A., Bley, F., Lefebvre, W., and Baroux, B.: Evolution of precipitate microstructures during the retrogression and re-ageing heat treatment of an Al–Zn–Mg–Cu alloy. Acta Mater. 58, 4814 (2010).Google Scholar
Sarkar, B., Marek, M., and Starke, E.A.: The effect of copper content and heat treatment on the stress corrosion characteristics of Al–6Zn–2Mg–X Cu alloys. Metall. Trans. A 12, 1929 (1981).Google Scholar
Feng, W., Xiong, B.Q., Zhang, Y.Q., Zhu, B.H., Liu, H.W., and He, X.Q.: Effect of heat treatment on the microstructure and mechanical properties of the spray-deposited Al–10.8Zn–2.8Mg–1.9Cu alloy. Mater. Sci. Eng., A 486, 648 (2008).Google Scholar
Park, J.K. and Ardell, A.J.: Microchemical analysis of precipitate free zones in 7075-A1 in the T6, T7 and RRA tempers. Acta Metall. Mater. 39, 591 (1991).Google Scholar
Xu, D.K., Birbilis, N., and Rometsch, P.A.. The effect of pre-ageing temperature and retrogression heating rate on the strength and corrosion behaviour of AA7150. Corros. Sci. 54, 17 (2012).Google Scholar
Feng, D., Zhang, X.M., Liu, S.D., Wang, T., Wu, Z.Z., and Guo, Y.W.: The effect of pre-ageing temperature and retrogression heating rate on the microstructure and properties of AA7055. Mater. Sci. Eng., A 588, 34 (2013).CrossRefGoogle Scholar
Nicolas, M. and Deschamps, A.: Characterization and modelling of precipitate evolution in an Al–Zn–Mg alloy during non-isothermal heat treatments. Acta Mater. 51, 6077 (2003).CrossRefGoogle Scholar
Ungár, T., Lendvai, J., Kovács, I., Groma, G., and Kovács-Csetényi, E.: The decomposition of the solid solution state in the temperature range 20-200°C in an Al-Zn-Mg alloy. J. Mater. Sci. 14, 671 (1979).CrossRefGoogle Scholar