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Recovery and recrystallization of the deformed, orderable alloy (Co78Fe22)3V

Published online by Cambridge University Press:  31 January 2011

R.W. Cahn*
Affiliation:
Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ, United Kingdom
M. Takeyama*
Affiliation:
Metals and Ceramics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831–6115
J.A. Horton
Affiliation:
Metals and Ceramics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831–6115
C.T. Liu
Affiliation:
Metals and Ceramics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831–6115
*
a)Address correspondence to this author.
b)Current address: National Research Institute for Metals, 2–3–12 Nakameguro, Meguro-ku, Tokyo 153, Japan.
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Abstract

An alloy of composition (Co78Fe22)3V, which orders to an L12 superlattice below a critical temperature (Tc) of 910 °C, was rolled to 25–50% reduction in the initially ordered condition and annealed at various temperatures above and below Tc and examined by hardness, tensile testing, optical and electron microscopy and dilatometry, in order to study the progress of recovery and recrystallization. Recrystallization was severely retarded on annealing below Tc; close to Tc, recrystallization was ≈ 300 × slower in the ordered than the disordered range. Although recrystallization started promptly, predominantly at grain boundaries, very rapid recovery-softening of the unrecrystallized regions progressively reduced the driving force for recrystallization and slowed it down drastically. However, at 770°and 500 °C, recovery-softening was replaced by some recovery-hardening (i.e., strain-age hardening). Above Tc, recrystallization was complete in a few seconds and a special annealing method was needed to measure such times accurately. Dilatometric measurements showed that most of the order destroyed by rolling was restored long before recrystallization began, but the restoration was never complete unless the alloy was heated up through Tc and then slow cooled. Electron microscopy showed no sign of any antiphase domains in recrystallized grains except for a few isolated domain boundaries on annealing at 770 °C. A model is proposed to rationalize the incidence of recovery-softening or strain-age hardening at different annealing temperatures.

Type
Articles
Copyright
Copyright © Materials Research Society 1991

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References

1Stoloff, N. S. and Davies, R. G., Prog. Mater. Sci. 13, 1 (1966).CrossRefGoogle Scholar
2Cahn, R. W., Proc. Symp. on High Temperature Aluminides and Intermetallics, edited by Whang, S. H., Liu, C. T., Pope, D., and Stiegler, J. O. (TMS, Warrendale, PA), April 1990, p. 245.Google Scholar
3Gottstein, G., Nagpal, P., and Kim, W., Mater. Sci. Eng. A108, 165 (1989).Google Scholar
4Jang, J. S. C. and Koch, C. C., J. Mater. Res. 5, 498 (1990).CrossRefGoogle Scholar
5Liu, C. T., Int. Metals Reviews 29, 168 (1984).Google Scholar
6Liu, C. T. and Inouye, H., Proc. 2nd Int. Conf. on Strength of Metals and Alloys, Asilomar (ASM, 1970), Vol. 1, p. 283.Google Scholar
7Liu, C. T. and Inouye, H., Metall. Trans. A 10A, 1515 (1979).CrossRefGoogle Scholar
8Braski, D. N., Carpenter, R. W., and Bentley, J., Acta Metall. 30, 799 (1982).CrossRefGoogle Scholar
9David, S. A., Braski, D. N., and Liu, C. T., Welding Journal, Welding Research Suppl. 65, 93–s (1986).Google Scholar
10Liu, C. T., J. Nucl. Mater. 104, part B, 1205 (1982).Google Scholar
11Liu, C. T. and Schulson, E. M., Metall. Trans. A 15A, 701 (1984).Google Scholar
12Mantl, S., Rothman, S. J., Nowick, L. J., and Braski, D. N., Philos. Mag. 50A, 591 (1984).Google Scholar
13Hutchinson, W. B., Besag, F. M. C., and Honess, C. V., Acta Metall. 21, 1685 (1973).CrossRefGoogle Scholar
14Gialanella, S. and Cahn, R. W., presented at MRS Symposium on High-Temperature Ordered Intermetallic Alloys, Boston, MA, November 1990, to be published in the Proceedings.Google Scholar
15Braski, D. N., Bentley, J., and Cable, J. W., Proc. 40th Ann. Meet. Electron Microscopy Soc. Amer., edited by Bailey, G. W. (Washington, DC, 1982), p. 692.Google Scholar
16Feder, R., Mooney, R., and Nowick, A. S., Acta Metall. 6, 266 (1958).CrossRefGoogle Scholar
17Okamoto, P. R., Rehn, L. E., Pearson, J., Bhadra, R., and Grimsditch, M., J. Less-Common Metals 140, 231 (1988).CrossRefGoogle Scholar
18Cahn, R. W. and Westmacott, K. H., to be published.Google Scholar
19Morris, D. G. and Morris, M. A., J. Mater. Sci. (to be published).Google Scholar
20 K. Lücke and Rixen, R., Z. Metallkde. 59, 321 (1978).Google Scholar
21Roessler, B., Novick, D. T., and Bever, M. B., Trans. TMS-AIME 227, 985 (1963).Google Scholar
22Vidoz, A. E., Lazarevic, D. P., and Cahn, R. W., Acta Metall. 11, 17 (1963).Google Scholar
23Strutt, P. R. and Dodd, R. A., Ordered Alloys: Structural Applications and Physical Metallurgy, edited by Kear, B. H., Sims, C. T., Stoloff, N. S., and Westbrook, J. H. (Claitor's, Baton Rouge, LA, 1970), p. 475.Google Scholar
24Rudy, M. and Sauthoff, G., Mater. Sci. Eng. 81, 525 (1987).CrossRefGoogle Scholar
25Kuper, A. B., Lazarus, D., Manning, J. R., and Tomizuka, C. T., Phys. Rev. 104, 1536 (1956).CrossRefGoogle Scholar
26Cahn, R. W., in Phase Transitions in Condensed Systems—Experiments and Theory, edited by Cargill, G. S. III, Spaepen, F., and Tu, K-N. (Mater. Res. Soc. Symp. Proc. 57, Pittsburgh, PA, 1987), p. 385.Google Scholar
27Stoloff, N. S., Strengthening Methods in Crystals, edited by Kelly, A. and Nicholson, R. B. (Elsevier, Amsterdam, 1971), p. 193.Google Scholar
28Marcinkowski, M. J., Order-Disorder Transformations in Alloys, edited by Warlimont, H. (Springer, Berlin, 1974), p. 364.CrossRefGoogle Scholar
29Stoloff, N. S. and Davies, R. G., Acta Metall. 12, 473 (1964).CrossRefGoogle Scholar
30Moine, R., Eymery, J. P., and Grosbras, P., Phys. Status Solidi B 46, 177 (1971).Google Scholar