Dynamic effects in the lamellar-rod eutectic transition
| Title | Dynamic effects in the lamellar-rod eutectic transition |
| Publication Type | Journal Article |
| Year of Publication | 2011 |
| Authors | Liu S, Lee JH, Trivedi R |
| Journal Title | Acta Materialia |
| Volume | 59 |
| Pages | 3102-3115 |
| Date Published | 05 |
| Type of Article | Article |
| ISBN Number | 1359-6454 |
| Accession Number | ISI:000290053100020 |
| Keywords | aluminum alloys, diffusion, directional solidification, eutectic solidification, interface dynamics, Lamellar-rod transition, stability, systems |
| Abstract | Critical experiments in the Al-Cu system are carried out to establish the conditions for the stability of rod and lamellar eutectics. It is shown that the instability of a lamella initiates locally through the formation of a sinusoidal perturbation, and the fastest growing wavelength of perturbation, which corresponds to the rod spacing, is related to the local lamella spacing. The instabilities in adjacent lamellae are observed to be out of phase to give rise to a hexagonal arrangement of rods at the transition. The specific relationship found between the unstable lamella spacing and the resulting rod spacing at the transition is then taken into account to develop a general model of the rod lamellar transition which also includes the relative undercooling and the presence of a spacing distribution. A microstructure map is presented which defines the regimes of rod, lamellar and mixed structures, which is shown to be in good agreement with the experimental results. (C) 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. |
| URL | <Go to ISI>://000290053100020 |
| DOI | 10.1016/j.actamat.2011.01.050 |
| Alternate Journal | Acta Mater. |
