Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-05T14:09:55.549Z Has data issue: false hasContentIssue false
  • English
  • Français

The Effect of Prestrain on Deformation of Ni3Al Single Crystals

Published online by Cambridge University Press:  26 February 2011

W. E. Dowling Jr.  and
R. Gibala
W. E. Dowling Jr.
Affiliation:
Department of Materials Science and Engineering, The University of Michigan, Ann Arbor 48109
R. Gibala
Affiliation:
Department of Materials Science and Engineering, The University of Michigan, Ann Arbor 48109
Get access

Abstract

Prestrain of bcc metals at temperatures T>0.2Tm decreases the flow stress at lower temperatures (T<O.15Tm) where the yield strength has a large negative temperature dependence. This investigation has examined the influence of prestrain on the flow stress of Ni3A1, for which the yield strength has a large positive temperature dependence above 25°C. Nickel-rich Ni3Al single crystals with axial orientations near <001> or <123> were prestrained in compression up to 20% shear strain at -196°C and subsequently compression tested at 550°C. Specimens near the <123> axial orientation were also prestrained at 550°C and then tested at -196°C. The initial flow stress of samples prestrained at - 196°C and tested 550°C was reduced up to 50% compared to samples solely compression tested at 550°C. The magnitude of the reduced flow stress and its extent as a function of plastic strain were dependent upon the amount of prestrain and orientation. Prestraining at 550°C and subsequent testing at -196°C increased the flow stress by as much as 60% over samples solely tested at -196°C. Dislocation substructures obtained from selected samples coupled with arguments based on dislocation dynamics and obstacle strengthening are used to explain the results.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 133: Symposium H – High-Temperature Ordered Intermetallic Alloys III , 1988 , 209
Copyright
Copyright © Materials Research Society 1989

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

1. Noebe, R.D. and Gibala, R., Structure and Deformation of Boundaries, Subramanian, K. and Imam, M.A., eds., p. 89, TMS-AIME, Warrendale, PA (1986).Google Scholar
2. Sethi, V.K. and Gibala, R., Acta Met., 25, 321, (1977).Google Scholar
3. Mulford, R.A. and Pope, D.P., Acta Met., 21, 1375, (1973).Google Scholar
4. Edington, J.W., Practical Electron Microscopy in Materials Science, (Van Nostrand Reinhold Ltd., New York, 1976), p. 14 8.Google Scholar
5. Takeuchi, S., Kuramoto, E., Yamamoto, T. and Taoka, T., Jap. J. App. Phys., 12, 1486, (1973).Google Scholar
6. Takeuchi, S. and Kuramoto, E., Acta Met., 21, 45, (1973).Google Scholar
7. Veyssiere, P., Horton, J.A., Yoo, M.H., and Liu, C.T., Philos. Mag. Lett., 56, 17, (1988).Google Scholar
8. Yamaguchi, M., Paidar, V., Pope, D.P. and Vitek, V., Philos. Mag. A, 45, 867, (1982).CrossRefGoogle Scholar
9. Yoo, M.H. and Liu, C.T., J. Mater. Res., 3, 845, (1988).Google Scholar
10. Dimiduk, D. M., Williams, J.C. and Thompson, A.W., to be published.Google Scholar
11. Staton-Bevan, A.E. and Rawlings, R.D., Philos. Mag., 32, 787, (1975).Google Scholar