About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
|
Frontiers in Solidification: An MPMD Symposium Honoring Jonathan A. Dantzig
|
Presentation Title |
Formation of Locked-lamellar Grains in a Slightly Hypereutectic Al-Al2Cu Alloy during Thin-sample Directional Solidification |
Author(s) |
Sabine Bottin-Rousseau, Silvère Akamatsu, Mehdi Medjkoune |
On-Site Speaker (Planned) |
Sabine Bottin-Rousseau |
Abstract Scope |
During directional solidification of many metallic alloys of near-eutectic concentration, the main morphological features of lamellar microstructures depend on the crystal orientation relationships (OR) in the two-phase solid, in addition to growth parameters and boundary conditions. This still remains partially understood. We studied experimentally the dynamics of lamellar patterns in thin Al-Al2Cu samples. This allowed us to observe the coupled-growth front in situ. Crystallographic analyses were performed ex situ. We identified a new family of ORs in hypo-eutectic samples, and the so-called Alpha-4 and Beta-6 ORs, which have been previously found in bulk Al-Al2Cu ingots, in hyper-eutectic samples. During growth, the lamellae are observed to dynamically lock on dense coincidence planes that characterize those ORs. We will highlight the crucial role of the initial solidification stages during which eutectic grains and ORs are selected. |
Proceedings Inclusion? |
Planned: |
Keywords |
Solidification, Aluminum, |