Abstract
A new type of brittle fracture was discovered in a Cu–Bi alloy bicrystal with a random misorientation interface. Macroscopically, fracture occurred along the interface with a low-energy release rate of order 50 Jm−2. Microscopically, the crack apparently propagated in a zigzag manner such that a cleavagelike fracture was produced, which consists of two sets of smooth {110} facets and one set of {100} facets with serrations corresponding to their intersections with {111} slip planes. Facet sizes are typically of order 1 by 5 μm or smaller. The very smooth facets and low-energy absorption suggest that a decohesion separation process has occurred along {110} planes, and the serrations suggest that substantial dislocation slip accompanied fracture of the {100} facets. The fracture surface morphology may be explained as the result of a similar morphology of Bi-induced microscopic faceting of the bicrystal interface or, instead, may result from fracture propagating in the vicinity of, but not quite along, the interface. Evidence is presented that favors the latter so that this is a rapid, cleavagelike, semiintergranular fracture that has not been observed in fee metals or alloys when an environment effect is not involved. Its faceted features resemble those of transgranular stress corrosion cracks in certain fee metals.
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References
E. Voce and A. P. C. Hallowes, J. Inst. Met. 73, 323 (1947).
E. D. Hondros and D. McLean, Philos. Mag. 29, 771 (1974).
A. M. Donald and L. M. Brown, Acta Metall. 27, 59 (1979).
S. Biggin, in the Proceedings of the 9th International Conference on Electron Microscopy, Toronto, 1978, Vol. 1, p. 600.
A. Fraczkiewicz and M. Biscondi, J. Phys. (Paris) 46, C4-497 (1985).
J. D. Russell and A. T. Winter, Scr. Metall. 19, 575 (1985).
S. P. Lynch, Scr. Metall. 13, 1051 (1979).
R. Liu, H. Narita, C. Altstetter, H. Birnbaum, and E. N. Pugh, Metall. Trans. A 11, 1563 (1980).
J. L. Nelson and J. A. Beavers, Metall. Trans. A 10, 658 (1979).
K. Sieradski, R. L. Sabatini, and R. C. Newman, Metall. Trans. A 15, 1941 (1984).
M. J. Kaufman, E. N. Pugh, and A. J. Forty, Presentation at the 2nd International Conference on Fundamentals of Fracture, Gatlinberg, Tennessee, 4–7 November 1985.
E. N. Pugh, Corrosion, NACE 41, 517 (1985).
K. Sieradski and R. C. Newman, Philos. Mag. A 51, 95 (1985).
B. Yan and C. Laird, Mater. Sci. Eng. 80, 59 (1986).
L. Buchinger and C. Laird, Mater. Sci. Eng. 76, 71 (1985).
Binary Alloy Phase Diagrams, edited by T. B. Massalski (American Society of Metals, Metals Park, OH, 1986), Vol. 1.
S. T. Thorpe, V. Erb, W. A. Miller, and K. T. Aust (private communication).
F. Moya, G. E. Moya-Gontier, F. Cabane-Brouty, and J. Oudar, Acta Metall. 19, 1189 (1971).
B. Aufray and J. Cabane, Scr. Metall. 15, 1339 (1981).
A. Pineau, B. Aufray, F. Cabana-Brouty, and J. Cabana, Acta Metall. 31, 1047 (1983).
B. Singh, R. W. Wook, and E.-A. Knabbe, J. Vac. Sci. Technol. 17, 29 (1980).
S. Chikwembani and J. Weertman, Scr. Metall. 19, 1499 (1985).
A. Donald, Philos. Mag. 34, 1185 (1976).
A. M. Donald and A. J. Craven, Philos. Mag. A 39, 1 (1979).
J. R. Michael and D. E. Williams, Metall. Trans. A 15, 99 (1984).
J. R. Rellick, C. J. McMahon, H. L. Marcus, and P. W. Palmberg, Metall. Trans. 2, 1492 (1971).
C. J. McMahon, E. Furubayashi, H. Ohtani, and H. C. Feng, Acta Metall. 24, 695 (1976).
W. R. Wagner, T. Y. Tan, and R. W. Balluffi, Philos. Mag. 29, 895 (1974).
G. H. Bishop, W. H. Hortt, and G. Q. Bruggeman, Acta Metall. 19, 37 (1971).
M. J. Weins and J. J. Weins, Philos. Mag. 26, 885 (1972).
J. R. Rice, in Chemistry and Physics of Fracture, edited by R. M. Latanision and R. H. Jones (Martinus Nijhoff, Dordrecht, The Netherlands, 1987) (to be published).
J. S. Wang, “Review of Data to Evaluate Segregation Effects on the Ductile–Brittle Transition in Cu–Bi Bicrystals, “ Progress Report, Harvard University, 1985.
P. M. Anderson, Ph.D. dissertation, Harvard University, 1986.
J. S. Wang, P. M. Anderson, and J. R. Rice, in Mechanical Behavior of Materials—V, edited by M. G. Yan, S. H. Zhang, and Z. M. Zheng (Pergamon, New York, 1987), p. 191.
M. Gittmann, B. Quantin, and Ph. Domonlin, Met. Sci. 17, 123 (1983).
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Wang, JS. A new type of brittle fracture in a fcc metal bicrystal with intergranular segregation. Journal of Materials Research 3, 16–28 (1988). https://doi.org/10.1557/JMR.1988.0016
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DOI: https://doi.org/10.1557/JMR.1988.0016