Abstract
Precipitation of rhenium in β–NiAl was studied by analytical and high resolution electron microscopy. Extended solid solutions were created by solidification processing, and the precipitation and hardening behavior were studied. Evidence suggests that rhenium is initially precipitated as disks parallel to {100} of β-NiAl. Subsequent growth produces either a rod morphology or a pair of twin-related rods that form the shape of a butterfly. The twin plane of the butterfly is {1011} and this plane is nearly parallel to {110} of β–NiAl. A twinning transformation given by K1 = {1011}, K2 = {1013}, η1 = <1012 >, and η2 = <3032> was determined for the butterfly-shaped particles. All of the precipitates exhibited an orientation relationship consisting of parallel close-packed planes and directions, i.e., (101//(0001) and [111]//[1210]. Performing the twinning transformation on a rhenium precipitate produces a variant rather than a new orientation relationship. After elevated temperature aging, a rod morphology was observed with the rod axes aligned parallel with either <121> or <131> of the β–NiAl matrix. A total of 24 different variants are possible based upon the observed orientation relationship and the two observed growth directions.
Similar content being viewed by others
References
R. Darolia, JOM 43, 44 (1991).
C.T. Sims, ASM Metals Handbook, 8th ed. (American Society for Metals, Metals Park, OH, 1961), Vol. 1, p. 1220.
P. L. Raffo and W. R. Witzke, Trans. AIME 245, 889 (1956).
D. P. Mason, D. C. Van Aken, and J. G. Webber, in Intermetallic Matrix Composites, edited by D. L. Anton, P.L. Martin, D. B. Miracle, and R. McMeeking (Mater. Res. Soc. Symp. Proc. 194, Pittsburgh, PA, 1990), pp. 341–348.
J. G. Webber and D. C. Van Aken, Scripta Metall. 23, 193 (1989).
K. Vedula, V. Pathare, I. Aslanidis, and R. H. Titran, in High-Temperature Ordered Intermetallic Alloys, edited by C. C. Koch, C. T. Liu, and N. S. Stoloff (Mater. Res. Soc. Symp. Proc. 39, Pittsburgh, PA, 1985), pp. 411–421.
D. P. Mason, D. C. Van Aken, R. D. Noebe, I. E. Locci, and K. L. King, in High Temperature Ordered Intermetallic Alloys IV, edited by L.A. Johnson, D. P. Pope, and J. O. Stiegler (Mater Res. Soc. Symp. Proc. 213, Pittsburgh, PA, 1991), pp. 1033–1038.
F. Laves, Theory of Alloy Phases (American Society for Metals, Metals Park, OH, 1956), pp. 124–198.
R. Darolia, D. F. Lahrman, R. D. Field, and A. J. Freeman, in High Temperature Ordered Intermetallic Alloys III, edited by C. T. Liu, A. I. Taub, N. S. Stoloff, and C. C. Koch (Mater. Res. Soc. Symp. Proc. 133, Pittsburgh, PA, 1989), pp. 113–118.
R.D. Noebe, R.R. Bowman, C.L. Cullers, and S.V. Raj, 3rd Annual HITEMP Review-1990, NASA CP-10051 (1990), pp. 20–21.
R.J. Wasilewski, Trans. Metall. Soc. AIME 236, 455 (1966).
J. W. Cahn and G. Kalonji, Solid-State Phase Transformations, edited by H. I. Aaronson, D. E. Laughlin, R. F. Sekerka, and C. M. Wayman (The Metallurgical Society, Inc., 1982), pp. 3–14.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Van Aken, D.C., Mason, D.P., Malhotra, S.G. et al. An electron microscopy study of the precipitation of rhenium in the B2 nickel aluminide. Journal of Materials Research 8, 2524–2533 (1993). https://doi.org/10.1557/JMR.1993.2524
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1557/JMR.1993.2524