| About this Abstract |
| Meeting |
2021 TMS Annual Meeting & Exhibition
|
| Symposium
|
Frontiers in Solidification Science VIII
|
| Presentation Title |
Coupled and Decoupled Eutectic Growth in a Transparent Irregular Eutectic Alloy |
| Author(s) |
Sabine Bottin-Rousseau, Samira Mohagheghi, Silvère Akamatsu, Melis Serefoglu |
| On-Site Speaker (Planned) |
Sabine Bottin-Rousseau |
| Abstract Scope |
We present an experimental study of irregular eutectic growth patterns during directional solidification of the transparent faceted/nonfaceted AMPD-SCN alloy in thin samples. Real-time observations were performed with a regular optical microscope. The pulling velocity V was varied between 0.01 and 2 µm/s. We identified three different two-phase growth regimes as a function of V: (i) quasi-steady decoupled growth at low V values, during which the leading tips of well-separated, needle-shaped AMPD crystals were growing ahead of the SCN matrix; (ii) unsteady coupled growth at intermediate V values, with frequent noncrystallographic branching of the AMPD crystals; (iii) two-phase fingers at higher velocities (destabilizing effect of residual impurities). The labile pinning of the solid(AMPD)-solid(SCN)-liquid trijunctions involving faceted interfaces was key to the observed morphological transitions. In particular, we discovered that noncrystallographic branching operated near the trijunctions.
Work financed by Campus France (PHC BOSPHORUS 39706RE) and TÜBİTAK (Grant no 217M089). |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Solidification, |