Numéro
J. Phys. IV France
Volume 03, Numéro C7, Novembre 1993
The 3rd European Conference on Advanced Materials and Processes
Troisiéme Conférence Européenne sur les Matériaux et les Procédés Avancés
Page(s) C7-2021 - C7-2026
DOI http://dx.doi.org/10.1051/jp4:19937322
The 3rd European Conference on Advanced Materials and Processes
Troisiéme Conférence Européenne sur les Matériaux et les Procédés Avancés

J. Phys. IV France 03 (1993) C7-2021-C7-2026

DOI: 10.1051/jp4:19937322

Grain boundary diffusion and motion associated with precipitation and dissolution in metallic systems

G. SOLÓRZANO1, 2

1  Depto. de Ciência dos Materiais e Metalurgia, Pontifícia Universidade Católica do Rio de Janeiro, 22452 Rio de Janeiro, Brazil
2  Dept. of Materials Science and Engineering, Massachusetts Institute of Technology, MIT Rm 13-5001, Cambridge MA 02139, U.S.A.


Abstract
The microstructural evolution resulting from the combination of grain boundary diffusion-controlled phase transformations in typical alloy systems is described. For this purpose discontinuous precipitation lamellar products in Cu-In and Ni-Sn binary alloys have been subjected to dissolution treatments. Examination of the resulting microstructures have shown that, depending on the alloy composition and annealing temperature, the dissolution could be discontinuous or continuous. In the former, the dissolution process is controlled by diffusion along migrating grain boundaries. In the latter, it is dominated by volume diffusion while the grain boundaries remain stationary. The most striking feature of the post-dissolution microstructure in these alloys is related with two phenomena observed within the previously transformed product : generation of dislocation arrangements or new dislocation-free grains, giving rise to a localized grain refinement. In the absence of any plastic deformation applied to the material, the role played by the internal stresses and the lamellar interfaces generated during the precipitation process is discussed, particularly as the energetic potential for the observed recovery and recrystallization phenomena.



© EDP Sciences 1993