Abstract
The compctition between the stable α phase and metastable ω phase to precipitate in a metastableβ phase matrix was investigated in the present study. Four binary Ti-Ni alloys with compositions between 20 and 35 at. pct Nb were air cooled to room temperature from 1000 °C and then aged at temperatures between 300 and 500 °C. For aging temperatures of 400 °C and lower it was found that the quench before aging enabled ω phase precipitates to grow to the exclusion of α precipitates. When specimens were directly aged at 400 °C only α precipitates were observed. Precipitates which could not be identified using SAD were observed in specimens of the 30 and 35 at. pct Nb alloys. All precipitation reactions became more sluggish as the niobium content of an alloy was increased. The results reported here form the second part of a study of the stable and metastable equilibria of the Ti-Nb alloy system.
Similar content being viewed by others
References
L. Kaufman and H. Bernstein:Computer Calculations of Phase Diagrams, Academic Press, New York, NY, 1970.
D. L. Moffat: Ph.D. Thesis, University of Wisconsin-Madison, 1985.
D.L. Moffat and D. C. Larbalestier:Metall. Trans. A, 1988, vol. 19A, pp. 1677–86.
F. H. Froes, C. F. Yolton, J. M. Capenos, M. G. H. Wells, and J. C. Williams:Metall. Trans. A, 1980, vol. 11A, pp. 21–31.
O. Lyon, C. Severac, and C. Servant:Phil. Mag. A, 1983, vol. 48(5), pp. 825–39.
B.A. Hatt and V.G. Rivlin:Brit. J. App. Phys., 1968, vol. 1(2), pp. 1145–49.
C. Baker and J. Sutton:Phil. Mag., 1969, vol. 19, pp. 1223–55.
B.S. Hickman:Trans. TMS-AIME, 1969, vol. 245, pp. 1329–35.
H. M. Flower, R. Davis, and D. R. F. West:Titanium and Titanium Alloys: Scientific and Technical Aspects, B.C Williams and A.F. Belov, eds., Plenum Press, New York, NY, 1982, vol. 3, pp. 1703–15.
D. Kramer and C. G. Rhodes:Trans. TMS-AIME, 1967, vol. 236, pp. 1612–15.
V. A. Vozilkin, N. N. Buynov, Yu. F. Bychkov, V. G. Vereshchagin, V.R. Karasik, G. B. Kurganov, and V. A. Mal’tsev:Phys. Met. Metallog., 1970, vol. 30(4), pp. 82–90.
O. Lyon:J. Less-Common Met., 1981, vol. 81, pp. 103–13.
J. P. Morniroli and M. Gantois:Mém. Sci. Rev. Métall., 1973, vol. 70(11), pp. 831–42.
W. L. Bond:Acta Cryst., 1960, vol. 13, pp. 814–50.
C. Barrett and T. B. Massalski:Structure of Metals, McGraw-Hill, New York, NY, 1966.
W.G. Brammer, Jr. and C. G. Rhodes:Phil. Mag., 1967, vol. 16, p. 477.
M.I. Buckett and D.C Larbalestier:Applied Superconductivity Conference Proceedings, paper MH-7, Baltimore, MD, 1986.
A.L.J. Chang, S.L. Sass, and W. Krakow:Acta Metall., 1976, vol. 24, pp. 29–36.
S. Hanada, M. Ozeki, and O. Izumi:Metall. Trans. A, 1985, vol. 16A, pp. 789–95.
M.K. Koul and J. F. Breedis:Acta Metall., 1970, vol. 18(6), pp. 579–88.
G. H. Narayanan and T. F. Archbold:Metall. Trans., 1970, vol. 1, pp. 2281–90.
J. C. Williams:Titanium Science and Technology, R. I. Jaffee and H.M. Burke, eds., Plenum Press, New York, NY, 1973, vol. 3, pp. 1433–94.
Author information
Authors and Affiliations
Additional information
Formerly a Graduate Student in the Materials Science Program at the University of Wisconsin-Madison
Rights and permissions
About this article
Cite this article
Moffat, D.L., Larbalestier, D.C. The compctition between the alpha and omega phases in aged Ti-Nb alloys. Metall Trans A 19, 1687–1694 (1988). https://doi.org/10.1007/BF02645136
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02645136