Abstract
Orthorhombic Ni3Mo has been observed as a product of a cellular precipitation reaction occurring at grain boundaries in both Ni-12Al-15Mo and a ternary eutectic Ni-12.8Al-22.2Mo (compositions in at. pct) when heat treated at intermediate temperatures (600 to 850 °C). Convergent beam electron diffraction and energy dispersive X-ray spectroscopy techniques have been employed to characterize the structure and composition of this phase in these alloys. Since this phase is usually heavily faulted, the diffraction symmetries are reduced, causing ambiguities in analysis. Therefore, a binary (nominally) stoichiometric Ni3Mo alloy was produced and heat treated in a manner designed to minimize faulting. Convergent beam patterns obtained from this material exhibited symmetries that identify it as having the mmm point group; further analysis of the diffraction patterns led to the conclusion that the space group is Pmmn. These patterns were then used to aid in the interpretation of those taken from the ternary alloys. Orthorhombic Ni3Mo was also observed within the grains of the ternary eutectic alloy following prolonged aging treatments; the orientation relationship between the Ni3Mo and the fee matrix was determined to be identical with that in the cellularly transformed regions.
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F.D. Lemkey: NASC-76115-30, Final Report on NAVAIR Contract N62269-75-C-0129, United Technologies Research Center, East Hartford, CT, December 1975.
H. Sprenger, H. Richter, and J.J. Nicki:J. Mater. Sci., 1976, vol. 11, p. 2075.
D.D. Pearson, B. H. Kear, and F. D. Lemkey:Int. Conf. on Creep and Fracture of Engineering Materials and Structures, B. Wilshire and D.R.J. Owen, eds., Proc. of Int. Conf. held at University College, Swansea (Pine Ridge Press), 1981, p. 213.
R. E. Andersen, A. R. Cox, T. D. Tillman, and E. C. van Reuth:Proc. of 2nd Int. Conf. on Rapid Solidification Processing, R. Mehrabian, B. H. Kear, and M. Cohen, eds., 1980, Claitor’s Publishing Division, Baton Rouge, LA, 1980, p. 416.
S. Saito and P.A. Beck:Trans. TMS-AME, 1959, vol. 215, p. 938.
G. van Tendeloo, R. De Ridder, and S. Amelinckx:Phys. Stat. Sol.(a), 1975, vol. 27, p. 457.
M. Yamamoto, F. Shohno, and S. Nenno:Trans. JIM, 1978, vol. 19, p. 475.
P. L. Martin, H. A. Lipsitt, and J. C. Williams:Proc. of 2nd Int. Conf. on Rapid Solidification Processing, R. Mehrabian, B.H. Kear, and M. Cohen, eds., Claitor’s Publishing Division, Baton Rouge, LA, 1980, p. 123.
P. L. Martin: Ph.D. Thesis, Carnegie-Mellon University, Pittsburgh, PA, 1982.
D. B. Snow, E. M. Breinan, and B. H. Kear:Superalloys 1980. J. K. Tien, S.T. Wlodek, H. Morrow, III, M. Gell, and G. E. Maurer, eds., ASM, Metals Park, OH, 1980, p. 189.
D.B. Snow:Rapidly Solidified Amorphous and Crystalline Alloys, B. H. Kear, B.C. Giessen, and M. Cohen, eds., Elsevier Science Publishing, New York, NY, 1982, p. 523.
E.M. Breinan, D. B. Snow, and C. O. Brown: Final Report No. R81-914346-8 on DARPA Contract N00014-78-C-0387, United Technologies Research Center, East Hartford, CT, January 1981.
J.W. Steeds: inIntroduction to Analytical Electron Microscopy, J.J. Hren, J.I. Goldstein, and D.C. Joy, eds., New York, NY, Plenum, 1979, p. 387.
B.F. Buxton, J. A. Eades, J.W. Steeds, and G.M. Rackham:Phil. Trans. R. Soc. London, 1976, vol. A 281, p. 171.
J. Gjonnes and A. F. Moodie:Acta Cryst., 1965, vol. 19, p. 65.
J. W. Steeds, G. M. Rackham, and M. D. Shannon:Electron Diffraction 1927-1977, Int. Conf. on Electron Diffraction, London, 1977 (Inst. Phys. Conf. Ser. No. 41; 0305-2346), P.J. Dobson, J.B. Pendry, and C. J. Humphreys, eds., Inst. of Physics, Bristol, 1978, p. 135.
International Tables for X-ray Crystallography, N. F. M. Henry and K. Lonsdale, eds., Kynoch Press, Birmingham, England, 1965, vol. 1, p. 133.
R. E. W. Casselton and W. Hume-Rothery:J. Less Common Metals, 1964, vol. 4, p. 436.
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Kaufman, M.J., Eades, J.A., Loretto, M.H. et al. A study of a cellular phase transformation in the ternary Ni- Ai- Mo alloy system. Metall Trans A 14, 1561–1571 (1983). https://doi.org/10.1007/BF02654382
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DOI: https://doi.org/10.1007/BF02654382