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On the Stress Anomaly of γ-TiAl

Published online by Cambridge University Press:  21 March 2011

Marc C. Fivel
Affiliation:
GPM2 / CNRS / INPG, B.P. 46, 38402 - St Martin d'Hères, FRANCE
Francois Louchet
Affiliation:
LTPCM / INPG / UJF, B.P. 75, 38402 - St Martin d'Hères, FRANCE
Bernard Viguier
Affiliation:
LIMAT, ENSCT, INP de Toulouse, 118 rte de Narbonne, 31077 Toulouse cedex 4, FRANCE
Marc Verdier
Affiliation:
LTPCM / INPG / UJF, B.P. 75, 38402 - St Martin d'Hères, FRANCE
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Abstract

A 3D mesoscopic simulation of dislocation behaviour is adapted to the case of γ-TiAl. It shows that, in the temperature range of the stress anomaly, ordinary dislocation motion essentially proceeds through a series of pinning and unzipping processes on screw dislocations. Pinning points are cross-slip generated jogs, whose density increases with temperature. Unzipping of cusps restores the screw character of the dislocation. The balance between pinning and unzipping becomes increasingly difficult as temperature raises, and results in dislocation exhaustion. All these features agree with the so-called “Local Pinning Unzipping” mechanism.

Type
Research Article
Copyright
Copyright © Materials Research Society 2001

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References

REFERENCES

1. Farenc, S., and Couret, A.,, in High Temperature Ordered Intermetallic Alloys, MRS Symposium Proc., Edited by Baker, I., Dariola, R., Whittenberger, J.D. and Yoo, M.N, 288, 465 (1993).Google Scholar
2. Louchet, F., and Viguier, B.,, Scripta Met. 31, 369 (1994).10.1016/0956-716X(94)90002-7Google Scholar
3. Louchet, F., and Viguier, B., Phil. Mag. A 71, 1313 (1995).10.1080/01418619508244376Google Scholar
4. Sriram, S., Dimiduk, D.M., Hazzledine, P.M., and Vasudevan, V.K., Phil. Mag. A 76, 965 (1997).10.1080/01418619708200010Google Scholar
5. Haussler, D., Bartsch, M, Aindow, M., Jones, I.P., and Messerschmidt, U., Phil. Mag. A 79, 1045 (1995).10.1080/01418619908210346Google Scholar
6. Gregori, F., Penhoud, P. and Veyssiere, P., Phil. Mag, in press.Google Scholar
7. Viguier, B., Hemker, K.J., Bonneville, J., Louchet, F., and Martin, J.L., Phil. Mag. A 71, 1295 (1995).Google Scholar
8. Louchet, F. and Viguier, B., Phil. Mag. A 80, 765 (2000).Google Scholar
9. Kubin, L.P., Canova, G.R., Condat, M., Devincre, B., Pontikis, V. and Bréchet, Y., in Solid State Phenom. 23 & 24, 455 (1992).Google Scholar
10. Verdier, M., Fivel, M. and Groma, I., in Modelling Simul. Mater. Sci. Eng. 6, 755770, (1998).10.1088/0965-0393/6/6/007Google Scholar
11. Viguier, B., Ph D. thesis no 1375, EPFL, May 2nd 1995.Google Scholar
12. Couret, A., Phil. Mag. A 79, 1977, (1999).10.1080/01418619908210404Google Scholar
13. Zghal, S., Menand, A. and Couret, A., Acta Mater. 46, 5899, (1998).Google Scholar
14. Louchet, F. and Lebyodkin, M., in Proc. 4th International Conference on High Temperature Intermetallics, San Diego, CA (USA), April 27th-May 1st 1997, Mat. Sci. Eng. A239–240, 804 (1997) (Edited by Pope, D.P., Liu, C.T, Wang, S.H. and Yamaguchi, M., Elsevier, 1997).Google Scholar