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Deformation mechanisms of an Ω precipitate in a high-strength aluminum alloy subjected to high strain rates

Published online by Cambridge University Press:  17 February 2011

K. Elkhodary ,
W. Lee ,
L.P. Sun ,
D.W. Brenner  and
M.A. Zikry
K. Elkhodary
Affiliation:
Department of Mechanical & Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695-7910
W. Lee
Affiliation:
Department of Mechanical & Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695-7910
L.P. Sun
Affiliation:
Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27587-7907
D.W. Brenner
Affiliation:
Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27587-7907
M.A. Zikry*
Affiliation:
Department of Mechanical & Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695-7910
*
a)Address all correspondence to this author. e-mail: [email protected]
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Abstract

The objective of this study was to identify the microstructural mechanisms controlling Ω precipitates’ contribution to the high strength and ductility of Al–Cu–Mg–Ag alloys subjected to high impact loading conditions. Three interrelated approaches were used: (i) HRTEM imaging of deformed Ω precipitates in ballistically impacted Al–Cu–Mg–Ag plates, (ii) microstructurally based finite element (FE) analysis based on specialized crystalline plasticity formulations, and (iii) molecular dynamics (MD) simulations of dislocation nucleation and emission. The FE and MD simulations detail the evolution of dislocation densities and dislocations at the Al/Ω interface, which are consistent with the experimentally observed multiplicity of shear cutting of thin Ω precipitates. Furthermore, the FE results indicate that unrelaxed tensile strains at the Al/Ω interface can inhibit localized deformation in the alloy.

Keywords

AlMicrostructureNanoscale
Type
Invited Feature Paper
Information
Journal of Materials Research , Volume 26 , Issue 4 , 28 February 2011 , pp. 487 - 497
Copyright
Copyright © Materials Research Society 2011

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Footnotes

This paper has been selected an as Invited Feature Paper.

References

REFERENCES

1.Eschbach, L., Solenthaler, C., Uggowitzer, P.J., and Speidel, M.O.: Strength and fracture toughness of spray formed Al–Cu–Mg–Ag Alloys. Mater. Sci. Technol. 15, 926 (1999).CrossRefGoogle Scholar
2.Polmear, I.J. and Couper, M.J.: Design and development of an experimental wrought aluminium-alloy for use at elevated-temperatures. Metall. Trans. A 19, 1027 (1988).CrossRefGoogle Scholar
3.Hono, K., Sano, N., Babu, S.S., Okano, R., and Sakurai, T.: Atom probe study of the precipitation process in Al–Cu–Mg–Ag alloys. Acta Metall. Mater. 41, 829 (1993).CrossRefGoogle Scholar
4.Howe, J.M. and Basile, D.P.: Minimum detectable solute concentration in atomic-resolution transmission electron-microscopy. Acta Crystallogr., Sect. A 44, 449 (1988).CrossRefGoogle Scholar
5.Cho, A. and Bes, B.: Damage tolerance capability of an Al–Cu–Mg–Ag alloy (2139). Mater. Sci. Forum 519–521, 603(2006).CrossRefGoogle Scholar
6.Cheeseman, B., Gooch, W., and Burkins, M.: Ballistic evaluation of aluminum 2139-T8, in 24th International Ballistics Symposium (New Orleans, LA, 2008).Google Scholar
7.Lee, W. and Zikry, M.: Microstructural characterization of a high strength aluminum alloy subjected to high strain-rate impact. Metall. Mater. Trans. A (2011, in press).CrossRefGoogle Scholar
8.Li, B.Q. and Wawner, F.E.: Dislocation interaction with semicoherent precipitates (omega phase) in deformed Al–Cu–Mg–Ag alloy. Acta Mater. 46, 5483 (1998).CrossRefGoogle Scholar
9.Orsini, V. and Zikry, M.: Void growth and interaction in crystalline materials. Int. J. Plast. 17, 1393 (2001).CrossRefGoogle Scholar
10.Zikry, M.A. and Kao, M.: Inelastic microstructural failure mechanisms in crystalline materials with high angle grain boundaries. J. Mech. Phys. Solids 44, 1765 (1996).CrossRefGoogle Scholar
11.Ashmawi, W. and Zikry, M.: Prediction of grain-boundary interfacial mechanisms in polycrystalline materials. J. Eng. Mater. Technol. 124, 88 (2002).CrossRefGoogle Scholar
12.Mughrabi, H.: A two parameter description of heterogeneous dislocation distributions in deformed metal crystals. Mater. Sci. Eng. 85, 15 (1987).CrossRefGoogle Scholar
13.Kameda, T. and Zikry, M.A.: Three dimensional dislocation-based crystalline constitutive formulation for ordered intermetallics. Scr. Mater. 38, 631 (1996).CrossRefGoogle Scholar
14.Knowles, K.M. and Stobbs, W.M.: The structure of (111) age-hardening precipitates in Al–Cu–Mg–Ag alloys. Acta Crystallogr., Sect. B 44, 207 (1988).CrossRefGoogle Scholar
15.Garg, A. and Howe, J.M.: Convergent-beam electron-diffraction analysis of the omega phase in an Al–4.0 Cu–0.5 Mg–0.5 Ag alloy. Acta Metall. Mater. 39, 1939 (1991).CrossRefGoogle Scholar
16.Ringer, S. and Hono, K.: Microstructural evolution and age hardening in aluminium alloys: Atom probe field-ion microscopy and transmission electron microscopy studies. Mater. Charact. 44, 101 (2000).CrossRefGoogle Scholar
17.Wang, S.C. and Starink, M.J.: Precipitates and intermetallic phases in precipitation hardening Al–Cu–Mg–(Li) based alloys. Int. Mater. Rev. 50, 193 (2005).CrossRefGoogle Scholar
18.Bonnet, R. and Loubradou, M.: Crystalline defects in a BCT Al2Cu(Theta) single crystal obtained by unidirectional solidification along. Phys. Status Solidi A 194, 173 (2002).3.0.CO;2-P>CrossRefGoogle Scholar
19.Ignat, M. and Durand, F.: Deformation lines on Al2Cu single crystals after creep in compression. Scr. Metall. 10, 623 (1976).CrossRefGoogle Scholar
20.Elkhodary, K., Sun, L., Irving, D.L., Brenner, D.W., Ravichandran, G., and Zikry, M.A.: Integrated experimental, atomistic, and microstructurally based finite element investigation of the dynamic compressive behavior of 2139 aluminum. J. Appl. Mech. 76, 051306 (2009).CrossRefGoogle Scholar
21.Elkhodary, K., Lee, W., Cheeseman, B., Brenner, D.W., and Zikry, M.A.: High strain-rate behavior of high strength aluminum alloys, in Nano- and Microscale Materials—Mechanical Properties and Behavior under Extreme Environments, edited by Misra, A., Balk, T.J., Huang, H., Caturla, M.J., and Eberl, C. (Mater. Res. Soc. Symp. Proc. 1137E, Warrendale, PA, 2009), 1137-EE05-31.Google Scholar
22.Polmear, I.J.: Light Alloys: Metallurgy of the Light Metals, 4th ed. (Elsevier/Butterworth-Heinemann, Burlington, MA, 2006), p. 38.Google Scholar
23.Embury, J.: Plastic-flow in dispersion hardened materials. Metall. Trans. A 16, 2191 (1985).CrossRefGoogle Scholar
24.El-Khodary, K., Lee, W., Sun, L., Cheeseman, B., Brenner, D., and Zikry, M.: Integrated experimental and computational modeling of the high strain-rate behavior of aluminum alloys, in Multiscale Polycrystal Mechanics of Complex Microstructures, edited by Raabe, D., Kalidindi, S., Radovitzky, R., and Geers, M. (Mater. Res. Soc. Symp. Proc. 1225E, Boston, MA, 2010).Google Scholar
25.Fonda, R., Cassada, W.A., and Shiflet, G.J.: Accommodation of the misfit strain surrounding (III) precipitates (Omega) in Al–Cu–Mg–(Ag). Acta Metall. Mater. 40, 2539 (1992).CrossRefGoogle Scholar
26.Hutchinson, C.R., Fan, X., Pennycook, S.J., and Shiflet, G.J.: On the origin of the high coarsening resistance of Ω plates in Al–Cu–Mg–Ag alloys. Acta Mater. 49, 2827 (2001).CrossRefGoogle Scholar
27.Hibbitt, , Karlson, , and Sorensen, : Abaqus Analysis User’s Manual, v6.8 (Dassault Systémes, 2008).Google Scholar
28.Liu, X., Xu, W., Foiles, S., and Adams, J.: Atomistic studies of segregation and diffusion in Al–Cu grain boundaries. Appl. Phys. Lett. 72, 1578 (1998).CrossRefGoogle Scholar
29.Sun, L., Irving, D.L., Zikry, M.A., and Brenner, D.W.: First-principles investigation of the structure and synergistic chemical bonding of Ag and Mg at the Al/Ω interface in a Al–Cu–Mg–Ag Alloy. Acta Mater. 57, 3522 (2009).CrossRefGoogle Scholar
30.Kelchner, C.L., Plimpton, S., and Hamilton, J.C.: Dislocation nucleation and defect structure during surface indentation. Phys. Rev. B: Condens. Matter 58, 11085 (1998).CrossRefGoogle Scholar
31.Zhu, A.W., Shiflet, G.J., and Starke, E.A.: First-principles calculations for alloy design of moderate temperature age-hardenable Al alloys. Mater. Sci. Forum 519–521, 35 (2006).CrossRefGoogle Scholar
32.Smithells, C.J.: Smithells Metals Reference Book, 8th ed. (Elsevier Butterworth-Heinemann, Burlington, MA, 2004).Google Scholar
33.Ali, A.A., Podus, G.N., and Sirenko, A.F.: Determining the thermal activation parameters of plastic deformation of metals from data on the kinetics of creep and relaxation of mechanical stresses. Strength Mater. 11, 496 (1979).CrossRefGoogle Scholar
34.Zikry, M. and Kao, M.: Inelastic microstructural failure modes in crystalline materials: The S33A ANS S11 high angle grain boundaries. Int. J. Plast. 13, 31 (1997).CrossRefGoogle Scholar
35.Zikry, M.: An accurate and stable algorithm for high strain-rate finite strain plasticity. Comput. Struct. 50, 14 (1994).CrossRefGoogle Scholar