About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
|
Advances in Powder and Ceramic Materials Science
|
Presentation Title |
Dislocation-based Room Temperature Plasticity in High Entropy Oxides |
Author(s) |
Xin Wang, Justin Cortez, Alexander D. Dupuy, William J. Bowman, Julie M. Schoenung |
On-Site Speaker (Planned) |
Xin Wang |
Abstract Scope |
Dislocations are common in metals, but their importance has not been fully recognized in ceramics. As a new class of materials, high entropy oxides (HEOs) have attracted significant interest due to their entropy-enhanced stability and compositionally tunable properties, which are required for various functional and structural applications. Here, we explore room temperature deformation mechanisms of (Co,Cu,Mg,Ni,Zn)O HEOs using nanoscratch and micropillar compression tests. The deformation microstructures after controlled deformation were systematically characterized using scanning/ transmission electron microscopy (S/TEM). We observe that, unlike most ceramics, HEOs with micron-sized grains exhibit prominent dislocation activity during room temperature deformation. The dislocation density observed can reach 1014 m-2, which is comparable with cold-worked alloys. In contrast, nanocrystalline samples exhibit intergranular crack propagation and grain boundary sliding, indicating that the mechanical behavior of HEOs can be tailored through microstructure. Orientation-dependent slip activation was further investigated to provide insights into the plastic anisotropy of this material. |
Proceedings Inclusion? |
Planned: |
Keywords |
Ceramics, Characterization, Mechanical Properties |