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In situ transmission electron microscope study of interface sliding and migration in an ultrafine lamellar structure

Published online by Cambridge University Press:  03 March 2011

L.M. Hsiung ,
J. Zhou  and
T.G. Nieh
L.M. Hsiung*
Affiliation:
Lawrence Livermore National Laboratory, Chemistry and Materials Science Directorate, Livermore, California 94551
J. Zhou
Affiliation:
Lawrence Livermore National Laboratory, Chemistry and Materials Science Directorate, Livermore, California 94551
T.G. Nieh
Affiliation:
The University of Tennessee, Department of Materials Science and Engineering, Knoxville, Tennessee 37996
*
a) Address all correspondence to this author. e-mail: [email protected] This paper was selected as the Outstanding Meeting Paper for the 2005 MRS Spring Meeting Symposium BB Proceedings, Vol. 880E.
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Abstract

The instability of interfaces in an ultrafine TiAl-(γ)/Ti3Al-(α2) lamellar structure by straining at room temperature has been investigated using in situ straining techniques performed in a transmission electron microscope. The purpose of this study was to obtain experimental evidence to support the creep mechanisms based upon the interface sliding in association with a cooperative movement of interfacial dislocations, which was proposed previously to rationalize a nearly linear creep behavior of ultrafine lamellar TiAl alloys. The results reveal that the sliding and migration of lamellar interfaces can take place simultaneously as a result of the cooperative movement of interfacial dislocations, which can lead to an adverse effect in the performance of ultrafine lamellar TiAl alloy.

Keywords

DislocationsGrain boundariesTransmission electron microscopy (TEM)
Type
Articles
Information
Journal of Materials Research , Volume 21 , Issue 10 , October 2006 , pp. 2453 - 2459
Copyright
Copyright © Materials Research Society 2006

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References

REFERENCES

1.Kim, Y-W., Dimiduk, D.M.: Progress in the understanding of gamma titanium aluminides. J. Metall. 43(8), 40 (1991).Google Scholar
2.Kim, Y-W.: Microstructural evolution and mechanical-properties of a forged gamma-titanium aluminide alloy. Acta Metall. Mater. 40, 1121 (1992).CrossRefGoogle Scholar
3.Wang, J.N., Schwartz, A.J., Nieh, T.G., Liu, C.T., Sikka, V.K., Clemens, D.R. Creep of a fine-grained, fully-lamellar, two-phase TiAl alloy at 760 °C, in Gamma Titanium Aluminides, edited by Kim, Y-W., Wagner, R., and Yamaguchi, M. (TMS, Warrendale, PA, 1995), p. 949.Google Scholar
4.Liu, C.T., Schneibel, J.H., Maziasz, P.J., Wright, J.L., Easton, D.S.: Tensile properties and fracture toughness of TiAl alloys with controlled microstructures. Intermetallics 4, 429 (1996).Google Scholar
5.Liu, C.T., Maziasz, P.J., Wright, J.L. Key microstructures controlling the mechanical properties of two-phase TiAl alloys with lamellar structures, in High-Temperature Ordered Intermetallic Alloys VII, edited by Koch, C.C., Liu, C.T., Stoloff, N.S., and Wanner, A. (Mater. Res. Soc. Symp. Proc. 460, Pittsburgh, PA, 1997), p. 83.Google Scholar
6.Hsiung, L.M., Nieh, T.G., Clemens, D.R.: Effect of extrusion temperature on the microstructure of a powder metallurgy TiAl-based alloy. Scripta Mater. 36, 233 (1997).CrossRefGoogle Scholar
7.Hsiung, L.M., Nieh, T.G.: Creep deformation of fully lamellar TiAl controlled by the viscous glide of interfacial dislocations. Intermetallics 7, 821 (1999).CrossRefGoogle Scholar
8.Hsiung, L.M., Nieh, T.G., Choi, B.W., Wadsworth, J.Interfacial dislocations and deformation twinning in fully lamellar TiAl. Mater. Sci. Eng. A 329–331 637 (2002).CrossRefGoogle Scholar
9.Hsiung, L.M. Interfacial control of creep deformation in ultrafine lamellar TiAl, in Nanomaterials for Structural Applications, edited by Berndt, C.C., Fischer, T.E., Ovid’ko, I., Skandan, G., and Tsakalakos, T. (TMS, Warrendale, PA, 2003), p. 287.Google Scholar
10.Hsiung, L.M., Nieh, T.G.: Microstructures and properties of powder metallurgy TiAl alloys. Mater. Sci. Eng., A 364, 1 (2004).Google Scholar
11.Liu, C.T., Maziasz, P.J., Larson, D.J. Effects of B and W additions on microstructures and mechanical properties of dual-phase lamellar TiAl alloys, in Interstitial and Substitutional Solute Effects in Intermetallics, edited by Baker, I., Noebe, R.D., and George, E.P. (TMS, Warrendale, PA, 1998), p. 179.Google Scholar
12.Mehrer, H., Sprengel, W., Denkinger, M. Diffusion in the intermetallic compounds TiAl and Co2Nb, in Diffusion in Ordered Alloys, edited by Fultz, B., Cahn, R.W., and Gupta, D. (TMS, Warrendale, PA, 1993), p. 51.Google Scholar
13.Chang, Y.A., Kieschke, R., DeKock, J., Zhang, M.X. Interfacial stabilities of high-temperature composite materials in control of interfaces, in Control of Interfaces in Metal and Ceramics Composites, edited by Lin, R.Y. and Fishman, S.G. (TMS, Warrendale, PA, 1993), p. 3.Google Scholar
14.Brooks, C.R. Heat treatment, structure and properties of nonferrous alloys, in Metals Handbook, edited by Boyer, H.E. and Gall, T.L. (ASM, Metals Park, OH, 1985) p. 28–66(T).Google Scholar
15.Larson, D.J., Liu, C.T., Miller, M.K.: Microstructural characterization of segregation and precipitation in α2+ γ titanium aluminides. Mater. Sci. Eng., A 239, 220 (1997).CrossRefGoogle Scholar
16.Du, X-W., Zhu, J., Zhang, X., Cheng, Z.Y., Kim, Y-W.: Creep induced α2 → β2 phase transformation in a fully-lamellar TiAl alloy. Scripta Mater. 43, 597 (2000).CrossRefGoogle Scholar
17.Larson, D.J., Liu, C.T., Miller, M.K.: Boron solubility and boride compositions in α2 + γ titanium aluminides. Intermetallics 5, 411 (1997).Google Scholar
18.Liu, C.T., Wright, J.L., Deevi, S.C.: Microstructures and properties of a hot-extruded TiAl containing no Cr. Mater. Sci. Eng., A 329–331, 416 (2002).CrossRefGoogle Scholar
19.Yamaguchi, M., Umakoshi, Y.: The deformation behavior of intermetallic superlattice compounds. Prog. Mater. Sci. 34, 1 (1990).CrossRefGoogle Scholar
20.Yamaguchi, M., Inui, H. TiAl Compounds for structural applications, in Structural Intermetallics, edited by Darolia, R., Lewandowski, J.J., Liu, C.T., Martin, P.L., Miracle, D.B., and Nathal, M.V. (TMS, Warrendale, PA, 1993), p. 127.Google Scholar
21.Yamamoto, Y., Takeyama, M., Matsuo, T.: Stability of lamellar microstructure consisting of γ/γ interfaces in Ti-48Al-8Nb single crystal at elevated temperatures. Mater. Sci. Eng., A 329–331, 631 (2002).CrossRefGoogle Scholar
22.Zhao, L., Tangri, K.: Variation in the dislocation-structure on lamellar Ti3Al/TiAl interfaces during deformation at different temperature. Philos. Mag. A 65, 1065 (1992).CrossRefGoogle Scholar
23.Mahon, G.J., Howe, J.M.: Transmission electron-microcopy investigation of interfaces in a two-phase TiAl alloy. Metall. Trans. A 21, 1655 (1990).CrossRefGoogle Scholar