Effect of Stepped Aging Treatment on Microstructure and Properties of AA7085 Aluminum Alloy

Abstract:

The effect of stepped aging treatment including two-stepped retrogression aging and retrogression reaging treatment on the mechanical properties, electrical conductivity and the microstructure of AA7085 has been investigated. Electron microscopy observations were used to analyze the microstructures and tensile fracture surfaces of AA7085 processed via various treatment schedules. Besides, X-ray diffractometer and differential scanning calorimeter were used to explore the thermodynamic factors of heat treatment. Through the investigation of the effect of the retrogression time on the properties and microstructure of AA7085, the optimized retrogression time was confirmed. The results of comparing retrogression aging and retrogression reaging treatment showed that through RRA treatment, higher conductivity and fracture toughness were gained. Through the optimized RRA treatment based on appropriate retrogression time, the tensile strength, elongation, fracture toughness and conductivity of AA7085 were raised to 660MPa, 12%,36.6MPa•m1/2and 38.1%IACS.

• Periodical: Advanced Materials Research (Volumes 228-229)
• Pages: 968-974
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.228-229.968
• Online since: April 2011
• Authors: Chun Mei Li, Zhi Qian Chen, Su Min Zeng, Nan Pu Cheng, Quan Li, Zhen Hua Geng
• Keywords: AA7085, Microstructure, Retrogression Reaging, Two-Stepped Aging

References

[1] J. Hirsch, B. Skrotzki and G. Gottstein: Aluminum Alloys(WILEY VCH Verlag GmbH & Co. K GaA., Germany 2008) p.202.

[2] R.T. Shuey, F. Barlat, M.E. Karbin and D.J. Chakrabarti: Melall. Mater. Trans. A, Vol. 40A (2009)No. 2, p.365.

[3] X.W. Li,B.Q. Xiong Y.A. Zhang: Sci China Ser E-Tech Sci, Vol. 52 (2009) No. 1, p.67.

[4] J.K. Park and A.J. Ardell: Metall. Trans., Vol. 15A(1984) No. 8, p.1531.

[5] K. Rajan,W. Wallace and J.C. Beddoes:J. Mater. Sci., Vol. 17(1982), p.2817.

[6] N.U. Deshpande A.M. Gokhale D.K. Denzer and J. Liu: Melall. Mater. Trans. A, Vol. 29(1998) No. 4, p.1191.

[7] T.C. Tsai and T.H. Chuang: Mater. Sci. Eng., A, Vol. 225 ( 1997) No. 1-2, p.135.

[8] L. Christodoulou and H.M. Flower: Acta Metall., Vol. 28 (1980) No. 10, p.481.

[9] L.K. Berg, GjΦnnes, J. Hansen and V et al: Acta mater., Vol. 49 (2001) No. 17, p.3443.

[10] T. Engdahl, V. Hansen and P. J. Warren: Mate. Sci. Eng., A, Vol. 327 (2002) No. 1, p.59.

[11] J.C. Werenskiold, A. Deschamps and Y. Brechet: Mater. Sci. Eng., A, Vol. 293 (2000) No. 1-2, p.267.

[12] M.J. Starink and X.M. Li: Metall Mater Trans A, Vol. 34A (2003) No. 4, p.899.

[13] M. Talianker and B. Cina: Melall Trans. A, Vol. 20A (1989) No. 10: p. (2087).