Strength and Toughness of 1.1wt% Li-Containing Al-Zn-Mg-Cu Alloys

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The effect of ageing processes on the toughness and the yield strength of the Li-containing Al-Zn-Mg-Cu alloys (Al-5.6%Zn-1.9%Mg-1.6%Cu-1.1%Li-0.24Cr) was investigated. The microstructure was observed by transmission electron microscopy, tensile test was performed at a rate of 1mm·s-1, fracture toughness was experimentally determined by the impact test, and the fracture modes had been assessed by image analysis of scanning electron microscopy micrographs. The strength of the Li-containing Al-Zn-Mg-Cu alloys treated at 120 °C is not more than 430MPa, which is very lower than that of 7075 alloys. The strength is comparable to that of 7075–T6 alloys after double-ageing or multi-ageing, however its ductility is lower than that of 7075-T6 alloys. The single-aged Li-containing alloys have high toughness. The multi-aged alloys become brittle. The fracture surface for the Li-containing Al-Zn-Mg-Cu alloys is intergranular, since the intergranular precipitation weakness the grain boundaries.

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Periodical:

Key Engineering Materials (Volumes 353-358)

Edited by:

Yu Zhou, Shan-Tung Tu and Xishan Xie

Pages:

392-395

Citation:

Z. K. Zhao et al., "Strength and Toughness of 1.1wt% Li-Containing Al-Zn-Mg-Cu Alloys", Key Engineering Materials, Vols. 353-358, pp. 392-395, 2007

Online since:

September 2007

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$38.00

[1] M. Ashby, D. Jones: Engineering Materials, vol. 1, (Butterworth Heinemann, Woburn, MA, USA 1996).

[2] Z.W. Huang, M.H. Loretto, R.E. Smallman and J. White: Acta Mater. Metall. Vol. 42 (1994), p.549.

[3] A. Sodergren and D.J. Lloyd: Acta Metall. Vol. 36 (1988), p.2107.

[4] Z.K. Zhao, Z.W. Du, T.T. Zhou, P.Y. Liu, C.Q. Chen: Mater. Forum Vol. 28 (2004), p.429.

[5] Y.L. Ji, T.T. Zhou, P.Y. Liu: Mater. Sci. Forum Vol. 475-479 (2005), p.325.

[6] T. Ogura, S. Hirosawa, T. Sato: Mater. Forum Vol. 28 (2004), p.1061.