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On the Shape Evolution of Coherent Precipitates: Discrete Atom Method

Published online by Cambridge University Press:  21 February 2011

Jong K. Lee  and
Jun H. Choy
Jong K. Lee
Affiliation:
Department of Metallurgical & Materials Engineering, Michigan Technological University, Houghton, MI 49931
Jun H. Choy
Affiliation:
Department of Metallurgical & Materials Engineering, Michigan Technological University, Houghton, MI 49931
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Abstract

Morphological evolution of coherent precipitates with arbitrary transformation strain is studied via a discrete atom method. With a purely dilatational misfit strain, a soft precipitate tends to have a plate-like equilibrium shape, whereas a hard precipitate takes up a shape of high symmetry such as a circle. If the stiffness is comparable between the matrix and precipitate, however, the equilibrium shape depends on the degree of anisotropy, misfit strain, size, and interfacial energy. Shape bifurcation phenomena from circular to rectangular shapes are also revealed during clustering. With either a tetragonal misfit strain of mixed signs or a pure shear misfit strain, a precipitate takes up a plate-like shape whose major axis lies along the direction containing an invariant line in accordance with the continuum elasticity prediction. Both elastic anisotropy and elastic inhomo-geneity exert little influence on the preferred orientation relationship. With a misfit strain of combined shear and dilatation, a precipitate follows an orientation and shape dictated by both components of the misfit strain.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 398: Symposium C – Thermodynamics and Kinetics of Phase Transformations , 1995 , 439
Copyright
Copyright © Materials Research Society 1998

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References

REFERENCES

1 Eshelby, J. D.: Prog. Solid Mech. 2, 89 (1961).Google Scholar
2 Wang, Y. and Khachaturyan, A. G.: Acta Metall. 43, 1837 (1995).Google Scholar
3 Thompson, M. E., Su, C. S. and Voorhees, P. W.: Acta Metall. 42, 2107 (1994).Google Scholar
4 Satoh, S. and Johnson, W. C.: Metall. Trans. 23A, 2761 (1992).Google Scholar
5 Gayda, J. and Srolovitz, D. J.: Acta Metall. 37, 641 (1989).Google Scholar
6 Lee, J. K.: Scripta Metall. 32, 559 (1995).Google Scholar
7 Lee, J. K.: Metall. Trans., in press.Google Scholar
8 Lee, J. K.: Micromechanics of Advanced Materials, edited by Chu, S. N. G. et al, (TMS, War-rendale,PA, 1995), p. 41.Google Scholar
9 Lee, J. K.: Phase Transformations during the Thermal/Mechanical Processing of Steel, edited by Hawbolt, E. B. and Yue, S. (The Metallurgical Society of CIM, Montreal, 1995), p. 49.Google Scholar
10 Hoover, W. G., Ashurt, W. T. and Olness, R. J.: J. Chem. Phys. 60, 4043 (1974).Google Scholar
11 Meshkinpour, M. and Ardell, A. J.: Mater. Sci. Eng. A185, 153 (1994).Google Scholar
12 Yoo, Y. S., Yoon, D. N. and Henry, M. F.: Metals and Mat. 1, 47 (1995).Google Scholar
13 Baskes, M. I. and Melius, C. F.: Phys. Rev. 20B, 3197 (1979).Google Scholar
14 Lee, J. K.: (unpublished work, 1995).Google Scholar
15 Howe, J. M. and Smith, D. A.: Acta Metall. 40, 2343 (1992).Google Scholar
16 Khachaturyan, A. G.: Theory of Structural Transformations in Solids. (Wiley & Sons, New York, NY, 1983), p. 248.Google Scholar
17 Dahmen, U. and Westmacott, K.: Acta Metall. 34, 475 (1986).Google Scholar
18 Johnson, W. C. and Cahn, J. W.: Acta Metall. 32, 1925 (1984).Google Scholar