|About this Abstract
||2020 TMS Annual Meeting & Exhibition
||High Entropy Alloys VIII
||Grain size dependent entropy-driven phase transformation in high entropy oxides.
||Alexander D. Dupuy, Xin Wang, Julie M Schoenung
|On-Site Speaker (Planned)
||Alexander D. Dupuy
High entropy oxide (HEO) materials contain at least five oxide components, which form a single phase that is stabilized through configurational entropy. A unique characteristic of HEO materials is their reversible entropy-driven phase transformation. This feature presents an opportunity to produce oxide materials with highly controlled phase states. Here we explore the impact of grain size on the entropic phase transition in (CoCuMgNiZn)O ceramics. Sourced nanopowders are mixed using planetary ball milling. These powders are simultaneously reacted and densified using free sintering and spark plasma sintering (SPS). By leveraging these processing routes, we show that it is possible to produce fully dense HEO ceramics with grain sizes spanning several orders of magnitude. Characterization of these ceramics reveals that the phase transformation in the nanocrystalline samples begins 200°C lower than the coarse-grained samples. Additionally, the morphology of the secondary phase is strongly influenced by the grain size of the HEO samples.
||Planned: Supplemental Proceedings volume; Planned: Supplemental Proceedings volume