Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-25T17:59:30.779Z Has data issue: false hasContentIssue false
  • English
  • Français

Kinetics of B2 and D03 Ordering: Theory

Published online by Cambridge University Press:  28 February 2011

L. Anthony  and
B. Fultz
L. Anthony
Affiliation:
California Institute of Technology, Dept. of Materials Science 138–78, Pasadena, CA 91125
B. Fultz
Affiliation:
California Institute of Technology, Dept. of Materials Science 138–78, Pasadena, CA 91125
Get access

Abstract

Monte-Carlo simulations (MCS) and the path probability method (PPM) were used to study disorder→order transformations in bcc alloys having the AB3 stoichiometry. Both methods used an explicit vacancy mechanism of ordering and an activated-state rate theory for the vacancy jumps. We studied the evolution of short-range order (SRO) as well as B2 and D03 long-range order (LRO) in alloys that began as random solid solutions. The growth rates of SRO and LRO were significantly higher for the PPM than for the MCS. We attribute this difference to improper handling of correlated vacancy motions in the PPM. The PPM also suffered from an artificial incubation time for the initiation of LRO. Both the MCS and the PPM showed that SRO has a tendency to develop in two stages. In the first stage there is a quick relaxation of the SRO by itself. In the second stage, which occurs with a longer time constant, the SRO and LRO grow simultaneously. Parametric plots of one order parameter against another, here termed “kinetic paths”, are discussed. A variety of different kinetic paths through the B2 and D03 order parameters can be predicted theoretically, depending on the choice of interatomic potentials. This range of calculated kinetic paths is broad enough to encompass our experimental results of SRO and LRO evolution in Fe3Al.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 186: Symposium I – Alloy Phase Stability and Design , 1990 , 181
Copyright
Copyright © Materials Research Society 1991

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] Kikuchi, R., Ann. Phys. 10 (1960) 127.Google Scholar
[2] Kikuchi, R., Prog. Theor. Phys. Suppl. 35 (1966) 1.Google Scholar
[3] Anthony, L. and Fultz, B., J. Mater. Res. 4 (1989) 1140.Google Scholar
[4] Fultz, B., Gao, Z.-Q., and Anthony, L., these proceedings.Google Scholar
[5] Fultz, B., J. Chem. Phys. 87 (1987) 1604.Google Scholar
[6] Fultz, B., J. Chem. Phys. 88 (1988) 3227.Google Scholar
[7] Fultz, B. and Anthony, L., in Diffusion in High Technology Materials, edited by Gupta, D., Romig, A. D. Jr., and Dayananda, M. A., (The Minerals, Metals and Materials Society, Warrendale, Pennsylvania, 1988).Google Scholar
[8] Fultz, B. and Anthony, L., Philos. Mag. Lett. 59 (1989) 237.Google Scholar
[9] Sato, H. and Kikuchi, R., Acta Metall. 24 (1976) 797.Google Scholar
[10] Gschwend, K., Sato, H., and Kikuchi, R., J. Chem. Phys. 69 (1978) 5006.Google Scholar
[11] Fultz, B., J. Mater. Res. in press.Google Scholar
[12] Anthony, L. and Fultz, B., J. Mater. Res. 4 (1989) 1132.Google Scholar
[13] Anthony, L. and Fultz, B., unpublished results.Google Scholar
[14] Warren, B. E., X-ray Diffraction, (Addison-Wesley, Reading, Massachusetts, 1969), Section 12.3.Google Scholar
[15] Bakker, H., in Diffusion in Crystalline Solids, edited by Murch, G. E. and Nowick, A. S., (Academic Press, New York, 1984), Chapter 4.Google Scholar