About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advances in Ceramic Materials and Processing
|
| Presentation Title |
Improved deformability of Co-free medium entropy oxides by controlled entropy destabilization |
| Author(s) |
Chang Liu, Ke Xu, Zhongxia Shang, Yang Chen, Debargha Paul, Yinghang Liu, Jeremy Gan, Shiyu Zhou, Edwin Garcia, Xinghang Zhang, Haiyan Wang |
| On-Site Speaker (Planned) |
Chang Liu |
| Abstract Scope |
High-entropy oxides (HEOs), such as (CoCuMgNiZn)O, exhibit excellent phase stability but remain intrinsically brittle. Here, we demonstrate a controlled entropy destabilization strategy to activate defect-mediated plasticity in a Co-free medium-entropy oxide (CuMgNiZn)O. Spark plasma sintering produces a rocksalt structure containing pre-existing Cu-rich secondary phases that serve as defect sources during deformation. In situ SEM micropillar compression, combined with transmission electron microscopy and crystallographic orientation mapping, reveals a temperature-dependent transition in deformation mechanisms. Crack-dominated failure at room temperature evolves into thermally activated dislocation motion at 400 °C and extensive dislocation glide with stacking-fault formation at 600 °C, resulting in pronounced strain hardening. Consequently, the fracture strain increases from 3% to 16%. These results demonstrate that controlled entropy destabilization effectively promotes dislocation nucleation, migration, and storage, providing a pathway to enhance the intrinsic deformability of multicomponent oxide ceramics. |
| Proceedings Inclusion? |
Planned: |