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Microstructures and Mechanical Properties of in-situ V-V3B2 Composites

Published online by Cambridge University Press:  26 February 2011

Sujing Xie  and
Easo P. George
Sujing Xie
Affiliation:
sxie@utk.edu, The University of Tennessee, Department of Materials Science and Engineering, 3700 Sutherland Ave., Knoxville, TN, 37996, United States
Easo P. George
Affiliation:
georgeep@ornl.gov, The University of Tennessee, Department of Materials Science and Engineering, Knoxville, TN, 37996, United States
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Abstract

A series of binary V-B alloys, with compositions spanning the eutectic, were produced by arc melting and drop casting. Microstructural examination revealed that the fully eutectic structure occurs at V-11B rather than V-15B as reported in the V-B phase diagram (all compositions in at.%). The V-11B eutectic was directionally solidified in an optical floating zone furnace, resulting in a composite microstructure consisting of a V matrix and flake or trigonal shaped V3B2 phase. The boride flake spacing (ë) decreases with increasing growth rate (R), following the relation ë2.56R=C, where C is a constant. TEM observations showed that the orientation relationship between the V and V3B2 phases is given by: [001]V // [001]V3B2 and (100)V // (100)V3B2. The growth direction and the V/V3B2 interface are parallel to the [001] direction and (100) planes in the two phases, respectively. Tensile tests were used to investigate the temperature dependence of the strength and ductility of the composite. At temperatures to 600°C, the yield strength of the eutectic is about 140 MPa higher than that of a commonly used vanadium solid-solution alloy, V-4Cr-4Ti. Surprisingly, the eutectic shows 5% tensile ductility at room temperature which increases to 10% as the test temperature is raised to 800°C.

Keywords

directional solidificationcompositeV
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 980: Symposium II – Advanced Intermetallic-Based Alloys , 2006 , 0980-II08-05
Copyright
Copyright © Materials Research Society 2007

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References

REFERENCES

1. Spear, K. E., Liao, P. K., Smith, J. F., Bulletin of Alloy Phase Diagrams 8, 447 (1987).Google Scholar
2. James, A. M., Lord, M. P., in Macmillan's Chemical and Physical Data, Macmillan, London, UK (1992).Google Scholar
3. Dean, J. A., in Lange's Handbook of Chemistry, McGraw-Hill, New York, USA, 14th edition (1992).Google Scholar
4. Zinkle, S. J., Rowcliffe, A. F., Stevens, C. O., Fusion Materials: Semi-annual Progress Report for Period Ending June 30, 1998, DOE/ER0313/24, 11 (1998).Google Scholar
5. T. Muroga et al., J. Nucl. Mater. 307–311, 547'554 (2002).Google Scholar
6. Henshall, G. A., Strum, M. J., Bewlay, B. P., Sutliff, J. A., Metall. Mater. Transactions A 28, 2555 (1997).Google Scholar
7. Bei, H., George, E. P., Kenik, E. A., Pharr, G. M., Z. Metallkd. 95, 6 (2004).Google Scholar
8. Lu, L., Lai, M. O., Toh, Y. H., Froyen, L., Mater. Sci. Eng. A 334, 163–172 (2002).Google Scholar
9. Lee, J. et al., Mater. Sci. Eng. A 277, 274–283 (2000).Google Scholar
10. Bei, H., George, E. P., Kenik, E. A., Pharr, G. M., Acta Mater. 51, 6241 (2003).Google Scholar
11. Oliver, W. C., Pharr, G. M., J. Mater. Res. 7, 1564 (1992).Google Scholar
12. Hunt, J. D., Hurle, D. T. J., Trans. Metall. Soc. AIME 242, 1043 (1968).Google Scholar
13. Hunt, J. D., Jackson, K. A., Trans. Metall. Soc. AIME 236, 843 (1966).Google Scholar
14. Xie, S., George, E. P., (to be submitted).Google Scholar
15. Jackson, K. A., Hunt, J. D., Trans. Metall. Soc. AIME 236, 1129 (1966).Google Scholar
16. Elliot, R., Glenister, S. M. D., Acta Mater. 28, 1489 (1980).Google Scholar