Hostname: page-component-586b7cd67f-tf8b9 Total loading time: 0 Render date: 2024-11-26T23:46:15.019Z Has data issue: false hasContentIssue false
  • English
  • Français

Deformation-induced γ → DI-α2 phase transformation occurring in the twin-intersection region of TiAl alloys

Published online by Cambridge University Press:  31 January 2011

C.L. Chen ,
W. Lu ,
L.L. He  and
H.Q. Ye
C.L. Chen
Affiliation:
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People’s Republic of China; and Graduate School of Chinese Academy of Sciences, Beijing 100039, People’s Republic of China
W. Lu
Affiliation:
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People’s Republic of China; and Graduate School of Chinese Academy of Sciences, Beijing 100039, People’s Republic of China
L.L. He*
Affiliation:
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People’s Republic of China
H.Q. Ye
Affiliation:
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People’s Republic of China
*
a)Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

Deformation-induced γ → DI-α2 phase transformation was verified to occur in the twin-intersection region of a Ti–45Al–8Nb (at.%) alloy compressed at room temperature. High-resolution image observations of the deformation-induced DI-α2 phase suggested that the orientation relationship between the DI-α2 and γ phases remained the typical one: (0001)DI−α2//{111}γ, [11¯20]DI−α2//〈101]γ. The conversion of stacking sequence from ordered face-centered tetragonal to ordered nonequilibrium hexagonal close-packed structure was accomplished by the movement of a/6〈11¯2] Shockley partial dislocations on every other {111}γ plane. Compositional analysis based on energy dispersive spectra revealed that the DI-α2 phase had the same composition as the matrix γ phase. No compositional diffusion occurred because the plastic deformation was carried out at room temperature. The strong stress concentration in the intersection region was the major force to induce the γ → DI-α2 phase transformation in the process of room-temperature compression.

Keywords

Phase transformationMicrostructureTransmission electron microscopy
Type
Articles
Information
Journal of Materials Research , Volume 22 , Issue 9 , September 2007 , pp. 2416 - 2422
Copyright
Copyright © Materials Research Society 2007

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1Kim, Y.W.Dimiduk, D.M.: Progress in the understanding of gamma titanium aluminides. JOM 43, 40 1991CrossRefGoogle Scholar
2Kim, Y.W.: Ordered intermetallic alloys. Part III: Gamma titanium aluminides. JOM 96, 30 1994CrossRefGoogle Scholar
3Appel, F., Sparka, U.Wagner, R.: Work hardening and recovery of gamma base titanium aluminides. Intermetallics 7, 325 1999CrossRefGoogle Scholar
4Maruyama, K., Yamaguchi, M., Suzuki, G., Zhu, H.L., Kim, H.Y.Yoo, M.H.: Effects of lamellar boundary structural change on lamellar size hardening in TiAl alloy. Acta Mater. 52, 5185 2004CrossRefGoogle Scholar
5Appel, F.Wagner, R.: Microstructure and deformation of two-phase γ-titanium aluminides. Mater. Sci. Eng., R 22, 187 1998CrossRefGoogle Scholar
6Calderon, H.A., Garibay-Febles, V., Umemoto, M.Yamaguchi, M.: Mechanical properties of nanocrystalline Ti–Al–X alloys. Mater. Sci. Eng., A 329–331, 196 2002CrossRefGoogle Scholar
7Kishida, K., Johnson, D.R., Masuda, Y., Umeda, H., Inui, H.Yamaguchi, M.: Deformation and fracture of PST crystals and directionally solidified ingots of TiAl-based alloys. Intermetallics 6, 679 1998CrossRefGoogle Scholar
8Wu, Y.Hwang, S.K.: Microstructural refinement and improvement of mechanical properties and oxidation resistance in EPM TiAl-based intermetallics with yttrium addition. Acta Mater. 50, 1479 2002CrossRefGoogle Scholar
9Kempf, M., Goken, M.Vehoff, H.: The mechanical properties of different lamellae and domains in PST-TiAl investigated with nanoindentations and atomic force microscopy. Mater. Sci. Eng., A 329–331, 184 2002CrossRefGoogle Scholar
10Appel, F., Oehring, M.Wagner, R.: Novel design concepts for gamma-base titanium aluminide alloys. Intermetallics 8, 1283 2000CrossRefGoogle Scholar
11Marketz, W.T., Fischer, F.D.Clemens, H.: Deformation mechanisms in TiAl intermetallics—Experiments and modeling. Int. J. Plast. 19, 281 2003CrossRefGoogle Scholar
12Kim, H.Y.Maruyama, K.: Stability of lamellar microstructure of hard orientated PST crystal of TiAl. Acta Mater. 51, 2191 2003CrossRefGoogle Scholar
13Ishikawa, N.Sato, A.: In situ observation of γ → α transformation of Fe particles in a Cu–Fe alloy. Philos. Mag. A 64, 387 1991CrossRefGoogle Scholar
14Liu, Y.N., Yang, H., Tan, G., Miyazaki, S.C., Jiang, B.H.Liu, Y.: Stress-induced FCC ↔ HCP martensitic transformation in CoNi. J Alloys Compds. 368, 157 2004CrossRefGoogle Scholar
15Waitz, T.Karnthaler, H.P.: The fcc to hcp martensitic phase transformation in CoNi studied by TEM and AFM methods. Acta Mater. 45, 837 1997CrossRefGoogle Scholar
16Mori, T., Oliver, E.C., Daymond, M.R.Withers, P.J.: Micromechanics of stress-induced martensitic transformation. Mater. Sci. Eng., A 378, 479 2004CrossRefGoogle Scholar
17Gao, Y., Zhu, J., Shen, H.M.Wang, Y.N.: Stress-induced phase transformation in two-phase TiAl intermetallic alloys. Scripta Metall. Mater. 28, 651 1993CrossRefGoogle Scholar
18Feng, C.R., Michel, D.J.Crowe, C.R.: The formation of Ti3Al within TiAl during the deformation of XD™ titanium aluminide. Scripta Metall. 23, 241 1989CrossRefGoogle Scholar
19Feng, C.R., Michel, D.J.Crowe, C.R.: Microstructural characteristics of two-phase titanium aluminides. Mater. Sci. Eng., A 145, 257 1991CrossRefGoogle Scholar
20Wang, J.G., Zhang, L.C., Chen, G.L., Ye, H.Q.Nieh, T.G.: Deformation-induced γ ↔ α2 phase transformation in a hot-forged Ti–45Al–10Nb alloy. Mater. Sci. Eng., A 239–240, 287 1997Google Scholar
21Wang, J.G., Zhang, L.C., Chen, G.L.Ye, H.Q.: Study on the stress-induced γ → α2 transformation in a hot-deformation Ti–45Al–10Nb alloy by high-resolution transmission electron microscopy. Mater. Lett. 31, 179 1997CrossRefGoogle Scholar
22Derder, C., Bonnet, R., Penisson, J.M.Frommeyer, G.: Evidence of stress-induced α2 → γ transformation in a Ti–30at.%Al alloy. Scripta Mater. 38, 757 1998CrossRefGoogle Scholar
23Zhang, Y.G., Ticheaar, F.D., Schapink, F.W., Xu, Q.Chen, C.Q.: An evidence of stress-induced α2 → γ transformation in a γ–TiAl-based alloy. Scripta Metall. Mater. 32, 981 1995CrossRefGoogle Scholar
24Ye, H.Q., He, L.L., Yu, R.Peng, Y.H.: HREM observation and compositional study of microstructure and phase transformation in TiAl-based and Cu–Al–Ni alloys. J. Electron Microsc. (Tokyo) 48(Suppl.), 1099 1999Google Scholar
25Skrotzki, B.: Crystallographic aspects of deformation twinning and consequences for plastic deformation processes in γ–TiAl. Acta Mater. 48, 851 2000CrossRefGoogle Scholar
26Sun, Y.Q., Hazzledine, P.M.Christian, J.W.: Intersections of deformation twins in TiAl I. Experimental observations. Philos. Mag. A 68, 471 1993CrossRefGoogle Scholar
27Marketz, W.T., Fischer, F.D., Kauffmann, F., Dehm, G., Bidlingmajer, T., Wanner, A.Clemens, H.: On the role of twinning during room temperature deformation of γ–TiAl based alloys. Mater. Sci. Eng., A 329, 177 2002CrossRefGoogle Scholar
28Zhang, J.X.Ye, H.Q.: Twin intersection in a deformed TiAl. Scripta Mater. 45, 133 2000CrossRefGoogle Scholar
29Wardle, S., Phan, I.Hug, G.: Analysis of twin intersections in TiAl. Philos. Mag. A 67, 497 1993CrossRefGoogle Scholar
30Zhang, Y.G.Chaturvedi, M.C.: Deformation twinning intersections in a γ–TiAl-based Ti–50 at.% Al–2 at.% Mn–1 at.% Nb alloy deformed at room temperature. Philos. Mag. A 68, 915 1993CrossRefGoogle Scholar
31Wolf, W., Podloucky, R., Rogl, P.Erschbaumer, H.: Atomic modeling of Nb, V, Cr, and Mn substitutions in γ–TiAl. 2: Electronic structure and site preference. Intermetallics 4, 201 1996CrossRefGoogle Scholar
32Zhang, Y.G., Han, Y.F., Chen, G.L., Guo, J.T., Wan, X.J.Feng, D.: Structural Intermetallics National Defence Industry Press Beijing, China 2001 787Google Scholar
33Howe, J.M.: Atomic mechanisms of precipitate plate growth. Philos. Mag. A 56, 31 1987CrossRefGoogle Scholar