Hostname: page-component-848d4c4894-nr4z6 Total loading time: 0 Render date: 2024-05-16T17:21:47.623Z Has data issue: false hasContentIssue false
  • English
  • Français

Nucleation & Growth of Precipitates in Transformations Driven by Diffusion

Published online by Cambridge University Press:  10 February 2011

N. Clavaguera  and
M.T. Clavaguera-Mora
N. Clavaguera
Affiliation:
Grup de Física de l'Estat Sòlid, Dept. E.C.M. Facultat de Física, Universitat de Barcelona, Diagonal 647, 08028-Barcelona, Spain
M.T. Clavaguera-Mora
Affiliation:
Grup de Física de Materials I, Dept. de Física, Universitat Autònoma de Barcelona, 08193-Bellaterra, Spain.
Get access

Abstract

A theoretical analysis of the transformation kinetics which accounts for nuclei, either prequenched or created homogeneously, and whose growth are controlled by diffusion is presented. The change in growth habit intervening during the transformation is analysed in terms of the evolution of the free energy difference between the precipitate and the matrix at the interface, ΔG1. In the Avrami formalism, this quantity accounts for the competition between interface and diffusion controlled growth whereas the nucleation events are driven by the free energy difference between the precipitate and the bulk matrix. Competition and selection of precipitate phases in highly undercooled melts using the CALPHAD approach for the evaluation of the free energies and the changes in diffusivity with concentration are analysed. Experimental vs. calculated data are discussed in some rapidly solidified metallic systems.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 481: Symposium P – Science and Technology of Semiconductor Surface Preparation , 1997 , 309
Copyright
Copyright © Materials Research Society 1998

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

REFERENCES

1. Clavaguera, N. & Clavaguera-Mora, M. T., Mat. Res. Soc. Symp. Proc. 398 (1996) 319.Google Scholar
2. Pradell, T., Crespo, D., Clavaguera, N. & Clavaguera-Mora, M.T., NanoStructured Materials, 8 (1997) 245.Google Scholar
3. Thompson, E. V. and Spaepen, F., Acta Metall., 31 (1983) 2021.Google Scholar
4. Baker, J.C. and Cahn, J.W., Solidification, Metals Park, OH, ASM, 1971, p.23.Google Scholar
5. Yerofeev, B.V. and Mitzkevitch, N.I., in “Reactivity of Solids”, Elsevier, Amsterdam, 1961, p. 273.Google Scholar
6. Christian, J.W., The theory of phase transformations in metals and alloys, Oxford, Pergamon Press, 1965, p. 377.Google Scholar
7. Spaepen, F. and Tumbull, D, in Grant, N.J. and Giessen, B.C. (Ed.), Proc. 2nd. Int. Conf. on Rapidly Quenched Metals, M.I.T. Press, 1976, p. 205.Google Scholar
8. See, for instance, ref 6.Google Scholar
9. Wagner, R. and Kampmann, R., in Phase Transformations in Materials, Haasen, P. (Volume Ed.), Materials Sci. & Techn. Vol.5, R.W. Cahn, P. Haasen & E.J. Kramer (Ed.), VCH, 1991, pp.213–304.Google Scholar
10. Ham, F.S., J. Phys. Chem. Solids, 6 (1958) 335.Google Scholar
11. Clavaguera-Mora, M. T., Thermochem. Acta (in press).Google Scholar
12. Crespo, D., Pradell, T., Clavaguera, N. and Clavaguera-Mora, M. T., Phys. Rev. B, 55 (1997) 3435.Google Scholar
13. Zhu, J., PhD Thesis, Autonomous University, Barcelona, 1996.Google Scholar
14. Clavaguera, N., Diego, J. A., Clavaguera-Mora, M. T., Inoue, A., NanoStructured Mater. 6 (1995) 485.Google Scholar
15. Pradell, T., Zhu, J., Crespo, D., Clavaguera, N. and Clavaguera-Mora, M. T., NanoStructured Mater., 8 (1997) 345.Google Scholar
16. Clavaguera, N. and Du, Y., J. Phase Equilibria 17, 1996.Google Scholar
17. Groebner, J., Clavaguera, N. and Clavaguera-Mora, M.T., (in preparation).Google Scholar
18. Clavaguera, N., Clavaguera-Mora, M.T. and Fontana, M., J. Mater. Res. (in press).Google Scholar