The Tensile Fracture of Ag-Containing Al-Li-Cu-Mg-Zr Alloys
The tensile properties and fracture characteristics of two kinds of Ag-containing Al-Li-Cu-Mg-Zr alloys with different aging conditions have been studied from 290 to 77 K. The results show that the tensile strength and ductility of the alloys improved significantly with a decrease in test temperature from 153 to 77 K, except for the elongation of some alloys in certain aging conditions. Planar slip behavior is the predominant deformation mode for the natural-, under-, and peak-aged samples when tested at room temperature, but the slip distribution is fairly homogeneous as the test temperature is reduced to 77 K. The different modes of tensile fracture are closely associated with the aging time and test temperatures. The improvement in cryogenic ductility of the alloys can be attributed to an increase in deformation homogeneity. The tensile fracture behavior of the alloys at ambient and cryogenic temperatures are discussed.
KeywordsTest Temperature Slip Band Naturally Aged Tensile Fracture Cryogenic Temperature
Unable to display preview. Download preview PDF.
- 1.J. Glazer, S. L. Verzasconi, R. R. Sawtell, and J. W. Morris, Jr., Mechanical behavior of aluminum-lithium alloys at cryogenic temperatures, Metall. Trans. A 18A: 1695 (1987).Google Scholar
- 5.K. Welpmann, Y.T. Lee, and M. Peters, Low temperature deformation phenomena of the Al-Li alloy 8090, Mater. Sci. Eng. Al29: 21 (1990).Google Scholar
- 6.J. W. Morris, Jr. and J. Glazer, Mechanical behavior of high-strength aluminum alloys at cryogenic temperatures, p. 713 in: “Cryogenic Materials ‘88,” R. P. Reed, Z. S. Xing, and E. W. Collings, eds., International Cryogenic Materials Conference, Boulder, Colorado (1988).Google Scholar
- 7.X. J. Jiang, Microstructure and tensile fracture mechanisms of Al-Li alloys containing Zn, Ag or Sc, Ph.D. Dissertation, Institute of Metal Research, Academia Sinica, Shenyang, China (1993).Google Scholar
- 9.X. J. Jiang and Y. Y. Li, Al-Li-Cu-Mg-Zr base alloys containing silver and/or scandium, Chinese patent application number 92106154.4 (April 27, 1992 ).Google Scholar