Abstract
An investigation has been carried out to study precipitation in a Cu-4% Ti binary and a Cu-2.1% Ti-2.4% Al ternary alloys which develop modulated microstructures upon ageing. Precipitate-free zones near the grain boundaries were observed on ageing immediately below a critical temperature representing the transition from the coherent to the incoherent region of the coherent phase diagram. In addition, a pronounced tendency for elastic interaction between the precipitate particles was detected, giving rise to aligned groups of precipitates containing a maximum of eight or nine particles in each group. At least near this critical temperature, decomposition occurs in the metastable region of the coherent phase diagram rather than in the spinodal region. The formation of the modulated structures in these alloys is, therefore, considered to arise not necessarily through spinodal decomposition. Continuous precipitation in a Cu-2.1% Ti-5% Al alloy is shown to result in spherical particles with no alignment. The effect of Al addition on the coherent solvus temperature is discussed in terms of a vacancy solute interaction mechanism.
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U. Hübner andG. Wassermann,Z. Metallk. 53 (1962) 152.
H. T. Michels, I. B. Cadoff andE. Levine,Met. Trans. 3 (1972) 667.
K. Saito andR. Watanabe,J. Phys. Soc. Japan 22 (1967) 681.
S. G. Prokopinskaya andE. V. Panchenko,Izv. Vyssh. Ucheb. Zaved, Tsvet Met. 10 (1967) 103.
J. A. Cornie, A. Datatta andW. A. Soffa,Met Trans. 4 (1973) 727.
T. Miyazaki, E. Yajima andH. Suga,Trans. JIM 12 (1971) 121.
A. J. Ardell andR. B. Nicholson with an appendix byJ. D. Eshelby,Acta Met. 14 (1966) 1295.
W. E. Krull, E. A. Starke, Jun. andR. W. Newman,Mat. Sci Eng. 9 (1972) 211.
A. D. Korotayev, A. T. Protason, O. V. Tsimenko andM. V. Lyubchenko,Fiz. Metal. Mettallov. 27 (1969) 127.
W. Gruhl andH. Cordier,Metall 11 (1957) 928.
R. Knights andW. Wilkes,Acta Met. 21 (1973) 1503.
D. E. Laughlin andJ. W. Cahn,Scripta Met. 8 (1974) 75.
J. H. Westbrook,Z. Krystallogr. 110 (1958) 21.
J. D. Embury andR. B. Nicholson,Acta Met. 13 (1965) 403.
M. J. Saarivirta andH. S. Cannon,Met. Prog. 76 (1959) 81.
G. W. Lorimer andR. B. Nicholson, “The Mechanism of Phase Transformations in Crystalline Solids” (Institute of Metals, London, 1969) p. 36.
J. E. Hilliard, “Phase Transformations” (American Society of Metals, Metals Park, Ohio, 1970) p. 497.
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Vaidyanathan, T.K., Mukherjee, K. Continuous precipitation in Cu-rich Cu-Ti binary and Cu-Ti-Al ternary alloys. J Mater Sci 10, 1697–1710 (1975). https://doi.org/10.1007/BF00554931
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DOI: https://doi.org/10.1007/BF00554931