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Solidification Processing Routes to High Aspect Ratio Reinforcements in γ-TiAl

Published online by Cambridge University Press:  21 February 2011

J. J. Valencia ,
J. P. A. Löfvander ,
J. Rösler ,
C. G. Levi  and
R. Mehrabian
J. J. Valencia
Affiliation:
Materials Department, University of California, Santa Barbara, CA 93106
J. P. A. Löfvander
Affiliation:
Materials Department, University of California, Santa Barbara, CA 93106
J. Rösler
Affiliation:
Materials Department, University of California, Santa Barbara, CA 93106
C. G. Levi
Affiliation:
Materials Department, University of California, Santa Barbara, CA 93106
R. Mehrabian
Affiliation:
Materials Department, University of California, Santa Barbara, CA 93106
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Abstract

Additions of ∼5%B1 and ∼9%Ta to binary γ-TiAl result in the formation of a monoboride isomorphous with TiB but containing Ta in solid solution. This boride exhibits strongly anisotropic growth from the melt, producing rod-like primary phases which are of potential interest for creep strengthening of the γ matrix. Fibrous borides with aspect ratios larger than ∼20 and volume fractions of ∼0.12 have been produced in arc-melted Ti-48AI-9Ta-4.3B alloys. Creep testing at 1255 K indicates that these “in-situ” composites have much higher creep strength than γ-TiAl, but the contribution of the reinforcements is relatively small compared with the solute-strengthening of the matrix.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 194: Symposium R – Intermetallic Matrix Composites I , 1990 , 89
Copyright
Copyright © Materials Research Society 1990

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References

1. Lipsitt, H.A., in High Temperature Ordered Intermetallic Alloys, ed. by C.C., Koch, C.T., Liu and N.S., Stoloff, (Mat. Res. Soc. Symp. Proc., 39 Pittsburgh, PA 1985), pp. 351–364.Google Scholar
2. Lipsitt, H.A., Shechtman, D., and Shafrik, R.E., Metall. Trans. A, 6A 1991 (1975).Google Scholar
3. Bao, G., Hutchinson, J.W., and McMeeking, R.M., this symposium.Google Scholar
4. He, M.Y., McMeeking, R.M., and Evans, A.G., this symposium.Google Scholar
5. Hyman, M.E., McCullough, C., Valencia, J.J., Levi, C.G., and Mebrabian, R., Metall. Trans. A, 20A, 1847 (1989).Google Scholar
6. Lundström, T., in Boron and Refractory Borides, ed. V.I., Matkovich, (Springer-Verlag, New York, 1977), pp. 351–376.Google Scholar
7. Valencia, J.J., McCullough, C., Rösler, J., Levi, C.G., and Mehrabian, R., in Solidification of Metal Matrix Composites ed. by P., Rohatgi (TMS, Warrendale, PA, 1990) (in press)Google Scholar
8. Hyman, M., McCullough, C., Levi, C.G., and Mehrabian, R., submitted for publication to Metall. Trans., 1990.Google Scholar
9. Levi, C.G., Valencia, J.J. and Mehrabian, R., in Processing of Structural Metals by Rapid Solidification, ed. by F.H., Froes and S.J., Savage, (ASM International, Metals Park, OH, 1987), pp. 1–12.Google Scholar
10. McCullough, C., Valencia, J.J., Levi, C.G. and Mehrabian, R., in Alloy Phase Stability and Design eds. Stocks, G.M., Pope, D.P. and Giamei, A.F., (Mat. Res. Soc. Symp. Proc., 186, Pittsburgh, PA 1990) (in press).Google Scholar
11. Rösler, J., Valencia, J.J., Levi, C.G., Evans-, A.G. and Mehrabian, R., this symposium.Google Scholar