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Hot-hardness comparisons among isostructural Be12X intermetallic compounds

Published online by Cambridge University Press:  31 January 2011

S.M. Bruemmer ,
B.W. Arey ,
J.L. Brimhall  and
J.P. Hirth
S.M. Bruemmer
Affiliation:
Pacific Northwest Laboratory, Richland, Washington 99352
B.W. Arey
Affiliation:
Pacific Northwest Laboratory, Richland, Washington 99352
J.L. Brimhall
Affiliation:
Pacific Northwest Laboratory, Richland, Washington 99352
J.P. Hirth
Affiliation:
Washington State University, Pullman, Washington 99164
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Abstract

Hot hardness has been measured in seven isostructural Be12X compounds: Be12Cr, Be12Mn, Be12V, Be12Mo, Be12Ti, Be12Ta, and Be12Nb. All vacuum-hot-pressed (VHP) materials exhibited similar hardness levels (800 to 1000 kg/mm2) at low temperatures (<600 °C), but sharply diverged at higher temperatures. Most compounds showed a sharp decrease in hardness above about one-half their melting temperatures except for Be12Nb and Be12Ti which maintained strength until higher temperatures. Ductile-brittle transition temperatures (DBTT's) of 600, 625, 690, 700, 700, and 850 °C were determined for Be12Cr, Be12Mn, Be12V, Be12Mo, Be12Ti, and Be12Nb, respectively. Hot-isostatically-pressed (HIP) and VHP Be12Nb heats both showed comparable behavior, indicating that the temperature required for macroscopic plasticity is not dependent on processing conditions. Differences in slip characteristics were observed between beryllides with similar melting temperatures, but differing DBTT's. Dislocations were activated on multiple slip systems in Bei2V during compressive deformation at 800 °C. Similar behavior was not observed in Be12Nb until test temperatures above 1000 °C. It is proposed that dislocation mobility may be related to the stability between Be12X and Be17X2 phases. Larger refractory metal atoms such as Nb may form faulted layers related to Be17X2 structures and thereby impede deformation at intermediate temperatures. Smaller atoms such as Cr, Mn, V, and Mo do not form a stable Be17X2 phase and thereby allow enhanced dislocation mobility at these temperatures.

Type
Articles
Information
Journal of Materials Research , Volume 8 , Issue 7 , July 1993 , pp. 1550 - 1557
Copyright
Copyright © Materials Research Society 1993

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References

REFERENCES

1Stonehouse, A. J.Paine, R. M. and Beaver, W.W.Mechanical Properties ofIntermetallic Compounds, edited by Westbrook, J. H. (John Wiley & Sons, New York, 1960), p. 297.Google Scholar
2Stonehouse, A. J.Mater. Design Eng., Feb. 1962.Google Scholar
3Aitken, E. A. and Smith, J. P. Properties of Beryllium Intermetallic Compounds, GEMP-105, GeneralElectric Company, 1961.Google Scholar
4Lewis, J. R.J. Metals 13, 357 (1961).Google Scholar
5Lewis, J. R.J. Metals 13, 829 (1961).Google Scholar
6Kendall, E. G.Ceramic Advanced Technology, Chap. 5, 1965, p. 143.Google Scholar
7Henager, C. H. Jr. , Jacobson, R. E. and Bruemmer, S. M.Mater. Sci. Eng. A152, 416 (1992).Google Scholar
8Bruemmer, S. M.Arey, B. W. and Henager, C. H. Jr. , in Inter-metallic Matrix Composites II, edited by Miracle, D. B.Anton, D.L. and Graves, J.A. (Mater. Res. Soc. Symp. Proc. 273, Pittsburgh, PA, 1992).Google Scholar
9Bruemmer, S. M.Chariot, L. A.Brimhall, J. L.Henager, C. H. Jr. , and Hirth, J. P.Philos. Mag. A 65–5, 108 3 (1992).Google Scholar
10Bruemmer, S.M.Chariot, L.A. and Hirth, J.P. unpublished research.Google Scholar
11Phase Diagrams of Binary Beryllium Alloys, edited by Okamoto, H. and Tanner, L. (ASM INTERNATIONAL, Metals Park, OH, 1987).Google Scholar
12Jacobson, R. E. High-Temperature Strength and Creep Resistance of Ben12Nb and Be12Nb2 Intermetallics, M. S. Thesis Washington State University, 1991.Google Scholar
13Kelly, A. and Groves, G. W.Crystallography of Crystal Defects (Addison-Wesley, Reading, MA, 1970), p. 178.Google Scholar
14Hirth, J. P. and Lothe, J., Theory of Dislocations, 2nd ed. (Krieger, Melbourne, FL, 1992), p. 688.Google Scholar
15Nieh, T. G. and Wadsworth, J., Script a Metall. et Mater. 24, 1489 (1990).Google Scholar
16Fleischer, R. L. and Field, R. D.Development Potential of Advanced Intermetallic Materials, WRDC-TR-90-4046 (Wright Research & Development Center, Wright-Patterson Air Force Base, OH, 1990).Google Scholar
17Fleischer, R.L. and Zabala, R.J.Metall. Trans. A20A, 1279 (1989).Google Scholar
18Raynor, G.V.Proc. 4th Int. Conf. on Beryllium (The Metals Society, 1977), p. 2/1.Google Scholar
19Brimhall, J.L.Chariot, L.A. and Bruemmer, S.M.Mater. Sci. Eng. A152, 76 (1992).Google Scholar
20Banerjee, D., Jacobson, L., Zindell, J., and Mitchell, T. E. in High Temperature Ordered Intermetallic Alloys IV, edited by Johnson, L.A., Pope, D. P. and Stiegler, J. O. (Mater. Res. Soc. Symp. Proc. 213, Pittsburgh, PA, 1991), p. 397.Google Scholar