|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Frontiers in Solidification: An MPMD Symposium in Honor of Michel Rappaz
||Dynamics of Locked Eutectics in Thin Samples and Phase Orientation Relationships
||Sabine Bottin-Rousseau, Gabriel Faivre, Silvère Akamatsu
|On-Site Speaker (Planned)
Eutectic solidification patterns can be dramatically influenced by crystallography, and their morphological features strongly eutectic-grain dependent. In lamellar-eutectic grains that present a special αβ orientation relationship, the interphase boundary are often « locked » onto a coincidence plane, which corresponds to a deep minimum of the boundary free energy as a function of its inclination. The lamellae grow then generally tilted. An approximate theory has been formulated, and essentially confirmed experimentally and numerically recently, which predicts the lamellar tilt angle as a function of the anisotropy function and the orientation of the eutectic grain. However, the large-scale dynamics of locked lamellar grains exhibits an irregular behavior that is poorly understood. We initiated a thin-sample directional solidification study of this dynamics in transparent and low-melting metallic alloys. We selected large eutectic grains with various anisotropies. We established the αβ orientation relashionship in those grains by analyzing pole figures (x-ray diffraction).