Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-02T23:03:48.660Z Has data issue: false hasContentIssue false
  • English
  • Français

AEM Microanalysis of Phase Equilibria in Ni3Al Intermetallic Alloys Containing Iron

Published online by Cambridge University Press:  25 February 2011

Bruce L. Bramfitt  and
Joseph R. Michael
Bruce L. Bramfitt
Affiliation:
Bethlehem Steel Corporation, Research Department, Bethlehem, PA 18016
Joseph R. Michael
Affiliation:
Bethlehem Steel Corporation, Research Department, Bethlehem, PA 18016
Get access

Abstract

In order to fully exploit the potential of Ni3Al alloys containing iron, it is necessary to characterize the phase relationships at the Ni-rich region of the Ni-Al-Fe ternary phase diagram. Due to the fine scale structures observed, a technique with high spatial resolution is required. X-ray microanalysis in the analytical electron microscope (AEM) provides a sufficiently high spatial resolution to determine the composition of the various phases occurring in this system. In this study, the isothermal section at 1000°C was evaluated in a series of alloys having nickel contents greater than 65 wt%. In Ni3Al, Fe can substitute for either Ni or Al in the ordered face-centered cubic lattice having an Ll2 structure. However, in substituting Fe for Ni one finds that the solubility limit is quickly exceeded at about 5 wt% Fe with the resultant formation of a ordered body-centered cubic (B2) phase at high temperature, which transforms martensitically upon quenching. Also, in substituting Fe for Al, the solubility limit is exceeded at about 5 wt% Fe with the formation of a disordered, face-centered cubic Ni-rich terminal solid solution. Thus, a very narrow range of alloy compositions exist where Fe can substitute for Ni and Al and preserve a single-phase L12 structure. It was found that the maximum solubility of Fe in Ni3Al at 1000°C was 17.3 wtpercnt; at 70.3 wt% Ni and 12.4 wt% Al.

Type
Articles
Information
MRS Online Proceedings Library (OPL) , Volume 62: Symposium Q – Materials Problem Solving with the Transmission Electron Microscope , 1985 , 201
Copyright
Copyright © Materials Research Society 1986

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. National Materials Advisory Board Report # 419, 1984.Google Scholar
2. High Temperature Ordered Intermetallic Alloys, edited by Koch, C.C., Liu, C.T. and Stoloff, N.S., MRS, vol.39, 1985.Google Scholar
3. Pope, D.P. and Ezz, S.S., Int. Met. Rev., 29, 1936 (1984).Google Scholar
4. Liu, C.T., Jemian, W., Inouye, H., Cathcart, J.V., David, S.A., Horton, J.A., and Santella, M.L., ORNL Report No. 6067, 1984.Google Scholar
5. Takasugi, T., Izumi, O. and Masahashi, N., Acta Metall., 33, 1259, (1985).CrossRefGoogle Scholar
6. Rivlin, V.G. and Raynor, G.V., Int. Met. Rev., 25, 79 (1980).Google Scholar
7. Taylor, A. Ph.D. Thesis, University of Manchester, 1936.Google Scholar
8. Bradley, A.J. and Taylor, A., Proc. Roy. Soc., A166, 353, (1938).Google Scholar
9. Bradley, A.J. and Taylor, A., J. Inst. Met., 66, 53 (1940).Google Scholar
10. Bradley, A.J., J. Iron Steel Inst., 163, 19 (1949).Google Scholar
11. Chandrasekaran, M. and Mukherjee, K., Mat. Sci. Eng., 13, 197 (1974).Google Scholar
12. Raghavan, M., Mueller, R.R., Vaughn, G.A. and Floreen, S., Met. Trans., 15A, 783 (1984).CrossRefGoogle Scholar
13. Raghavan Ayer, Mueller, R.R. and Kline, C.F., Analytical Electron Microscopy -1984, edited by Williams, D.B. and Joy, D.C. (San Francisco Press, Inc.:), p. 170.Google Scholar
14. Arai, K.I., Tsutsumitake, H. and Ohmori, K., Trans. Japan Inst. Met., 25, 855 (1984).CrossRefGoogle Scholar
15. Murty, Y.V. and Adler, R.P.I., J. Mat. Sci., 17, 1945 (1982).Google Scholar
16. Cliff, C. and Lorimer, C.W., J. of Micros., 103, 203 (1975).Google Scholar
17. Roe, D.A., Scott, V.D. and Love, G., Quantitative Microanalysis with High Spatial Resolution, edited by Lorimer, C.W., Jacobs, M.H. and Doig, P. (The Metals Society- London, 1981), p. 57.Google Scholar
18. Williams, D.B., Practical Analytical Electron Microscopy in Materials Science, (Philips Electronic Instruments, Inc., Mahwah, NJ -1984), p. 75.Google Scholar
19. Hansen, M. and Anderko, K., Constitution of Binary Alloys, 2nd ed. (McGraw Hill - New York, 1958) p. 119.Google Scholar
20. Ochai, S., Oya, Y. and Suzuki, T., Acta Metall., 32, 289, (1984).Google Scholar