Theory of rod eutectic growth under far-from-equilibrium conditions: Nanoscale spacing and transition to glass

TitleTheory of rod eutectic growth under far-from-equilibrium conditions: Nanoscale spacing and transition to glass
Publication TypeJournal Article
Year of Publication2012
AuthorsTrivedi R, Wang N
Journal TitleActa Materialia
Volume60
Pages3140-3152
Date Published04
Type of ArticleArticle
ISBN Number1359-6454
Accession NumberWOS:000303952000062
Keywordsalloys, glass transition, metallic glass, model, Non-equilibrium, RAPID, rapid solidification conditions, Rod eutectics, solidification
Abstract

The growth of eutectic under large undercooling conditions is important in obtaining nanoscale composite microstructures. Many glass-forming eutectic systems also exhibit a fine rod eutectic microstructure and often show a direct transition from eutectic to glass with increasing undercooling at the interface. A theoretical model of rod eutectic growth is developed in this paper, which quantitatively evaluates the system and growth parameters that will give rise to large undercooling at the interface. In addition to the diffusion and capillary undercooling, the model incorporates the effects of a sharp decrease in the diffusion coefficient that is exhibited by fragile glass-forming systems, the presence of highly nonlinear liquidus lines at large undercooling, and the effects of non-equilibrium at the interface. The results of the model are then discussed to obtain an insight into the system and growth parameters that are critical for obtaining a large undercooling at the eutectic interface, which is important in the design of nanoscale composite materials and in the selection of potential glass-forming systems. Published by Elsevier Ltd. on behalf of Acta Materialia Inc.

URL<Go to ISI>://WOS:000303952000062
DOI10.1016/j.actamat.2012.02.020
Alternate JournalActa Mater.