Identification of Cleavage Planes in an Al3Ti-Base Alloy by Electron Channeling in the SEM


Selected area electron channeling patterns were used to identify the cleavage planes in a polycrystalline Al3Ti-base alloy having the L12 structure. In order to do this unambiguously in the scanning electron microscope (SEM), one needs to know that the cleavage facet from which any given channeling pattern is obtained is indeed normal to the electron beam. We accomplished this by utilizing a recently-developed technique in which an optical microscope with a short depth of focus is inserted in the SEM column and used to measure the elevations of several points on the cleavage facets. By appropriately tilting and rotating the sample, and using the optical microscope to measure elevations, it was possible to orient the facets normal to the beam. The cleavage planes in a cast and extruded alloy having an equiaxed grain structure were compared with those in a directionally-solidified (DS) alloy of the same composition. Of the eight cleavage facets examined in the DS material, six were of the {110} type and two were of the {111} type. Of the six facets examined in the cast and extruded material, two each were of the {110} and {111} types, and one each were of the {100} and {013} types. Although it cannot be said that all possible cleavage planes have been identified in this alloy, the availability of several low-strength cleavage planes apparently exacerbates its brittleness.

This is a preview of subscription content, access via your institution.


  1. 1.

    J. L. Murray in “Binary Alloy Phase Diagrams,” edited by T. B. Massalski, J. L Murray,L. H. Bennett, and H. Baker (American Society for Metals, Metals Park, OH, 1986), vol. 1 p. 175.

  2. 2.

    P. Villars and L. D. Calvert, “Pearson’s Handbook of Crystallographic Data for Intermetallic Phases” (American Society for Metals, Metals Park, OH, 1985), vol. 1, p. 476.

  3. 3.

    M. Yamaguchi, Y. Umakoshi, and T. Yamane, in “High Temperature Ordered IntermetaHic Alloys II (Proc. Mater. Res. Soc. Symp.),” edited by N. S. Stoloff, C. C. Koch, C. T. Liu, and O. Izumi (Materials Research Society, Pittsburgh, PA, 1987), vol. 81, p. 275.

  4. 4.

    C. T. Liu, Int. Met. Rev. 29, 168 (1984).

    CAS  Article  Google Scholar 

  5. 5.

    A. Raman and K. Schubert, Zeitschrift fur Metallkunde. 56, 99 (1965).

    CAS  Google Scholar 

  6. 6.

    A. Seibold, Zeitschrift fur Metallkunde. 72, (1981).

  7. 7.

    S. C. Huang, E. L Hall, and M. F. X. Gigliotti, J. Mater. Res. 3, 1 (1988).

    CAS  Article  Google Scholar 

  8. 8.

    J. Tarnacki and Y.-W. Kim, Scripta Metall. 22, 329 (1988).

    CAS  Article  Google Scholar 

  9. 9.

    W. D. Porter and W. C. Oliver, Presented at the TMS-AIME Annual Meeting, Phoenix, AZ, (1988).

  10. 10.

    W. D. Porter and W. C. Oliver (unpublished research). Oak Ridge National Lab. 1988.

  11. 11.

    E. P. George, W. D. Porter, H. M. Henson, W. C. Oliver, and B. F. Oliver, To appear in J. Mater. Res. 4 (1). Jan/Feb 1989.

  12. 12.

    A. Aoki and O. Izumi, Acta Metall. 27, 807 (1979).

    CAS  Article  Google Scholar 

  13. 13.

    A. Aoki and O. Izumi, J. Mater. Sci. 14, 1800 (1979).

    CAS  Article  Google Scholar 

  14. 14.

    R. Ayres and D. F. Stein, Acta Metall. 19, 789 (1971).

    CAS  Article  Google Scholar 

Download references

Author information



Corresponding author

Correspondence to E. P. George.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

George, E.P., Porter, W.D. & Joy, D.C. Identification of Cleavage Planes in an Al3Ti-Base Alloy by Electron Channeling in the SEM. MRS Online Proceedings Library 133, 311 (1988).

Download citation