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Miniaturized Disk-Bend Testing of Ni3 Al: Effect of Stoichiometry and Boron Content

Published online by Cambridge University Press:  26 February 2011

H. Li  and
A. J. Ardell
H. Li
Affiliation:
Department of Materials Science and Engineering, University of California, Los Angeles, CA 90024
A. J. Ardell
Affiliation:
Department of Materials Science and Engineering, University of California, Los Angeles, CA 90024
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Abstract

The results of miniaturized disk-bend tests on samples of Ni 3Al of different stoichiometry and boron content are presented. The yield strengths and ductilities of alloys containing 24, 25 or 26 %Al. either boron-free or doped with 0.3 or 0.35 %B, were measured. Specimens 3 mm in diameter and approximately 200 μm thick were tested, some of these having been cut from the grip sections of previously tested tensile bars. The yield strengths were in excellent agreement with the results obtained from the uniaxial tensile tests. The load-displacement curves for the brittle alloys (all but the boron-doped 24 %Al alloy) exhibited a maximum load corresponding to crack initiation. The shapes of the deformed specimens confirmed the assumption that they deform as if they were clamped even though they are not. The fracture surfaces of the brittle alloys are consistent with intergranular failure. Nevertheless, the ductility of the alloys increases with decreasing Al content and decreasing grain size, even for the boron-free alloys which are all brittle. The fracture stress of the boron-doped 26 %Al alloy is about 30% greater than that of the boron-free alloy. It is argued that this is most likely a consequence of the depletion of aluminum at grain boundaries, coupled with boron segregation. Independent evidence suggests that this should increase the cohesive strength of grain boundaries in the boron-doped 26 %Al alloy.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 213: Symposium Q – High-Temperature Ordered Intermetallic Alloys IV , 1990 , 757
Copyright
Copyright © Materials Research Society 1991

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References

REFERENCES

1. Lucas, G. E.. Metal. Trans. 21A 1105 (1990).Google Scholar
2. Manahan, M. P., Browning, A. E., Argon, A. S. and Harling, O. K., in The Use of Small- Scale Specimens for Testing Irradiated Material, edited by Corwin, W. R. and Lucas, G. E. (ASTM STP 888, American Society for Testing and Materials, Philadelphia, PA. 1986) pp. 17–49.Google Scholar
3. Harling, O. K., Lee, M., Sohn, D.-S., Kohse, G. and Lau, C. W.,The Use of Small- Scale Specimens for Testing Irradiated Material , pp. 50–65.Google Scholar
4. Li, H., Chen, F. C. and Ardell, A. J.. (unpublished, submitted to Metall. Trans.).Google Scholar
5. Schulson, E. M., Weihs, T. P., Viens, D. V. and Baker, I., Acta Met., 33, 1587 (1985).Google Scholar
6. Schulson, E. M., Weihs, T. P., Baker, I., Frost, H. J. and Horton, J. A., Acta Met. 34, 1395 (1986).Google Scholar
7. Baker, I. (private communication).Google Scholar
8. Roarke, R. J. and Young, W. C.. Formulas for Stress and Strain, 5th ed. (McGraw-Hill, New York, 1975), p. 366.Google Scholar
9. Pottebohm, H., Neite, G. and Nembach, E., Mater. Sci. Engr. 60, 189 (1983).CrossRefGoogle Scholar
10. Huang, F. H., Hamilton, M. L. and Wire, G. L., J. Nucl. Tech. 57, 234 (1982).Google Scholar
11. Weihs, T. P., Zinoviev, V., Viens, D. V. and Schulson, E. M., Acta Met. 35, 1109(1987).Google Scholar
12. Khadkikar, P. S., Vedula, K. and Shabel, B. S., Metall. Trans. 18A, 425 (1987).Google Scholar
13. Kim, M. S., Hanada, S., Watanabe, S. and Izumi, O., Trans. Japan Inst. Met. 29, 274 (1988).Google Scholar
14. Chen, S. P., Voter, A. F. and Srolovitz, D. J., Scripta Met. 20, 1389 (1986).Google Scholar
15. Shulson, E. M., Xu, Y., Munroe, P. R, Guha, S. and Baker, I., (unpublished, submitted to Metall. Trans. A).Google Scholar
16. Liu, C. T., White, C. L. and Horton, J. A., Acta Met. 33, 213 (1985).Google Scholar
17. Horton, J. A., Miller, M. K., Liu, C. T., George, E. P. and Bentley, J., in High-Temperature Ordered Intermetallic Alloys III, edited by Liu, C. T., Taub, A. I., Stoloff, N. S. and Koch, C. C. (Mat. Res. Soc. Symp. Proc. 133, Pittsburgh, PA 1989 pp. 89–97.Google Scholar
18. Chen, S. P., Voter, A. F., Albers, R. C., Boring, A. M. and Hay, P. J., J. Mater. Res. 5, 955 (1990).Google Scholar