Abstract
A methodology is presented to characterize the crystallography of individual fracture surface facets. Electron backscatter patterns (EBSP’s) from a metallographic section through a facet identify grain orientation, and quantitative tilt fractography identifies facet orientation; these results are combined to establish fracture facet crystallography. For this technique, facet electropolishing is not required, the facet alignment procedure is accurate and quick, and the method can be generalized to different microstructures, test environments, or facet orientations. Method accuracy is illustrated for 25 to 50 μm fatigue crack facets in an unrecrystallized Al–Li–Cu alloy (AA2090) that has 5 μm thick subgrains in elongated grains that are 10 to 200 μm thick. The fine subgrain structure and tortuous fatigue crack profile precludes the use of other diffraction techniques for determining AA2090 facet crystallography. EBSP and tilt fractography results demonstrate that vacuum fatigue cracks in AA2090 are nearly parallel to local {111} planes.
Similar content being viewed by others
References
C.S. Barrett and T.B. Massalski, Structure of Metals (McGraw-Hill, New York, 1966), p. 416.
D.A. Meyn, Trans. ASM 61, 52 (1968).
R. M. N. Pelloux, Trans. ASM 62, 281 (1969).
G. G. Garrett and J. F. Knott, Acta Metall. 23, 841 (1975).
D.L. Davidson and D. Eylon, Metall. Trans. A 11A, 837 (1980).
J. A. Wert and W. M. Robertson, Metallography 15, 367 (1982).
E. I. Meletis, in Fracture, Measurement of Localized Deformation by Novel Techniques, edited by W. W. Gerberich and D. L. Davidson (TMS-AIME, Warrendale, PA, 1984), p. 87.
D. N. Fager, M. V. Hyatt, and H. T. Diep, Scripta Metall. 20, 1159 (1986).
S. P. Lynch, Acta Metall. 36, 2639 (1988).
G.R. Yoder, P.S. Pao, M.A. Imam, and L.A. Cooley, Scripta Metall. 22, 1241 (1988).
H. K. Birnbaum, in Hydrogen Effects on Material Behavior, edited by N. R. Moody and A. W. Thompson (The Minerals, Metals & Materials Society, 1990), p. 639.
A.P. Reynolds and G.E. Stoner, Metall. Trans. A 22A, 1849 (1991).
C. Q. Chen and H. X. Li, in Aluminum-Lithium 5, edited by T. H. Sanders and E. A. Starke, Jr. (Materials and Component Engineering Publications Ltd., Wardley Heath, U.K., 1989), p. 972.
R. Tintillier, H. J. Gudladt, V. Gerold, and J. Petit, in Aluminum-Lithium 5, edited by T. H. Sanders and E. A. Starke, Jr. (Materials and Component Engineering Publications Ltd., Wardley Heath, U.K., 1989), p. 1135.
Y. B. Xu, L. Wang, Y. Zhang, Z. G. Wang, and Q. Z. Hu, Metall. Trans. A 22A, 723 (1991).
D.L. Davidson, Int. Metals Rev. 29, 75 (1984).
J. A. Kozubowski, M-J. Lii, and W. W. Gerberich, Scanning 9, 237 (1987).
K. T. Venkateswara Rao and R. O. Ritchie, Int. Mater. Rev. 37, 153 (1992).
R. S. Piascik and R. P. Gangloff, Metall. Trans. A (1993, in press).
D. C. Slavik and R. P. Gangloff, Fatigue ‘93, edited by J. P. Bailon and J. I. Dickson (EMAS, West Midlands, U.K., 1993), Vol. II, pp. 757–765.
D.J. Dingley, Scanning Electron Microscopy II, 569 (1984).
D. J. Dingley and K. Baba-Kishi, Scanning Electron Microscopy II, 383 (1986).
S. I. Wright and B. L. Adams, Metall. Trans. A 23A, 759 (1992).
V. Randle, B. Ralph, and D. Dingley, Acta Metall. 36, 267 (1988).
F. Barlat, J. C. Brem, and J. Liu, Scripta Metall. 27, 1121 (1992).
ASTM Standard E647-88A, in the 1989 Annual Book of ASTM Standards (ASTM, Philadelphia, PA, 1989), Vol. 03.01, p. 646.
D.C. Slavik, C.P. Blankenship, Jr., E.A. Starke, Jr., and R.P. Gangloff, unpublished results.
R.S. Piascik and R.P. Gangloff, Metall. Trans. A 22A, 2415 (1991).
K.V. Jata and E.A. Starke, Jr., Metall. Trans. A 17A, 1011 (1986).
J. F. Knott, Fundamentals of Fracture Mechanics (John Wiley and Sons, New York, 1979), p. 89.
A.J. Wilkinson and D.J. Dingley, Acta Metall. 39, 3047 (1991).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Slavik, D.C., Wert, J.A. & Gangloff, R.P. Determining fracture facet crystallography using electron backscatter patterns and quantitative tilt fractography. Journal of Materials Research 8, 2482–2491 (1993). https://doi.org/10.1557/JMR.1993.2482
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1557/JMR.1993.2482