Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-17T21:26:44.419Z Has data issue: false hasContentIssue false

Elevated Temperature Slow Plastic Deformation of NiAl/TiB2 Particulate Composites

Published online by Cambridge University Press:  22 February 2011

R. K. Viswanadham
Affiliation:
Formerly with Martin Marietta Laboratories, 1450 South Rolling Rd., Baltimore, MD 21227-3898; currently at Multi-Metals 715 Gray St., Louisville, KY 40202
J. Daniel Whittenberger
Affiliation:
NASA-Lewis Research Center, Cleveland, OH 44135
S. K. Mannan
Affiliation:
Martin Marietta Laboratories, 1450 South Rolling Rd., Baltimore, MD 21227-3898
B. Sprissler
Affiliation:
Martin Marietta Laboratories, 1450 South Rolling Rd., Baltimore, MD 21227-3898
Get access

Abstract

To enhance the high temperature strength of aluminides, NiAl–iB2 composites with particulate contents up to 30 vol. pct. were made by XDTM synthesis and hot pressed to full density. Microstructures of these composites were characterized by optical, scanning and transmission electron microscopy (TEM). The average size of the TiB2 particles was about 1 μm, and the average grain size of the NiAl matrix was on the order of 10 μm. Elevated temperature compression testing was conducted on these composites in air at 1200 and 1300 K with strain rates varying from 10−4 to 10−7 s−1. Flow strengths were found to increase with increasing TiB2 content; for example, the 20 vol. pct. TiB2 composite was three times stronger than unreinforced NiAl. Post test TEM analysis showed that the primary feature of the dislocation substructure of deformed NiAl was well defined subgrain boundaries, whereas the structure of the higher volume fraction composites consisted of a very high density of tangled dislocations, loops and subgrain boundaries connecting particles. These observations suggest that TiB2 particles can stabilize a completely different dislocation structure than that normally found in NiAl.

Type
Research Article
Copyright
Copyright © Materials Research Society 1988

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

1. Viswanadham, R.K., Mannan, S.K. and Sprissler, B., “Nickel Aluminide /Titanium Diboride Composites” Martin Marietta Laboratories TR 87-66c, 1987.Google Scholar
2. Hansen, M. and Anderko, K., Constitution of Binary Alloys, (McGraw Hill, New York, 1958). Additional Supplements by R. P Elliot, 1965 and F. A. Shrunk, 1969.Google Scholar
3. Bradley, A.J. and Taylor, A., Proc. R. Soc. Series A 159, 56 (1937).Google Scholar
4. Fetzer, E. and Gerasimoff, P., Z. Metallk. 50, 187 (1959).Google Scholar
5. Imai, V. and Kumazawa, M., Sci. Rept. Res. Inst. Tohoku Univ. 11 (1959) [referenced by E. A. Aitken in Intermetallic Compounds edited by Westbrook, J. H. (John Wiley, New York 1967) p. 507.Google Scholar
6. Whittenberger, J.D., J. Mat. Sci. 22, 394 (1987).Google Scholar
7. Grala, E.M.. in Mechanical Properties of Intermetallic Compounds, edited by Westbrook, J.H. (John Wiley, New York, 1960) pp. 358404.Google Scholar
8. Schulson, E.M. and Barker, D.R., Scripta Metall. 17, 519 (1983)CrossRefGoogle Scholar
9. Li, J.C.M. and Sanday, S.C., Acta Metall. 34, 537 (1986).Google Scholar
10. Sherman, M. and Vedula, K., J. Mater. Sci. 21, 1974 (1986).Google Scholar
11. Whittenberger, J.D., Mater. Sci. Eng. 57, 77 (1983).Google Scholar
12. Whittenberger, J.D., Mat. Sci. Eng., 73, 87 (1985).Google Scholar
13. Pathare, V.M., PhD Thesis, Case Western Reserve University, 1987.Google Scholar
14. Yang, W.J. and Dodd, R.A., Met. Sci J. 7, 41 (1973).CrossRefGoogle Scholar
15. Raj, S.V. and Pharr, G.M., Mat. Sci. Eng. 81, 217 (1986).Google Scholar
16. Sherby, O.D., Klundt, R.H. and Miller, A.K., Met. Trans. A 8A, 843 (1977).Google Scholar