Nucleation and growth of precipitates in transformations driven by diffusion
- Univ. de Barcelona (Spain)
- Univ. Autonoma de Barcelona, Bellaterra (Spain)
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 analyzed in terms of the evolution of the free energy difference between the precipitate and the matrix at the interface, {Delta}G{sup 1}. 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 analyzed. Experimental vs. calculated data are discussed in some rapidly solidified metallic systems.
- OSTI ID:
- 323479
- Report Number(s):
- CONF-971201-; TRN: IM9911%%92
- Resource Relation:
- Conference: 1997 fall meeting of the Materials Research Society, Boston, MA (United States), 1-5 Dec 1997; Other Information: PBD: 1998; Related Information: Is Part Of Phase transformations and systems driven far from equilibrium; Ma, E. [ed.] [Louisiana State Univ., Baton Rouge, LA (United States)]; Atzmon, M. [ed.] [Univ. of Michigan, Ann Arbor, MI (United States)]; Bellon, P. [ed.] [Univ. of Illinois, Urbana, IL (United States)]; Trivedi, R. [ed.] [Ames Lab., IA (United States)]|[Iowa State Univ., Ames, IA (United States)]; PB: 703 p.; Materials Research Society symposium proceedings, Volume 481
- Country of Publication:
- United States
- Language:
- English
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