|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Bulk Metallic Glasses XV
||Tracking Metastable Phase Selection during Devitrification in a Metallic Glass
||Lin Zhou, Fanqiang Meng, Shihuai Zhou, Taehoon Kim, Ryan Ott, Ralph Napolitano, Matthew J. Kramer
|On-Site Speaker (Planned)
Devitrification of metallic glasses can lead to a wide range of metastable phases, many not accessible during solidification from the melt. Advanced in situ characterization capabilities now provide a window for real-time observation of phase transition down to atomic level. By precisely control the sample’s temperature (<0.1°C) using a MEMS microheater in an aberration corrected Titan Themis scanning transmission electron microscope, we are able to measure competitive nucleation and growth involving metastable phases crystallizing from an Al90Sm10 glass. The growth of a large unit cell crystalline phase (Al120Sm22) is accompanied by intermittent formation of Al-clusters at the growth front, modifying the crystal-glass interface movement and promoting a “cauliflower” microstructure. Subsequent solid-solid phase transformations showed a complex eutectic growth of three phases. The obtained structural and dynamic information provides valuable insight into metastable phase selection when coupled with atomic scale modeling. Challenges and opportunities for such detailed studies will be discussed.
||Planned: Supplemental Proceedings volume