| About this Abstract |
| Meeting |
Materials Science & Technology 2019
|
| Symposium
|
Materials for Nuclear Applications
|
| Presentation Title |
High-Entropy Carbide Ceramics for Extreme Environments |
| Author(s) |
Fei Wang, Xueliang Yan, Yongfeng Lu, Michael Nastasi, Bai Cui |
| On-Site Speaker (Planned) |
Bai Cui |
| Abstract Scope |
Novel high-entropy carbide ceramic, e.g., (Zr0.25Ta0.25Nb0.25Ti0.25)C, has been developed as a candidate material for high-temperature and irradiation extreme environments. X-ray diffraction suggests that it has a single-phase rock salt structure, in which the four metal elements likely share the cation position while the C element occupies the anion sublattice. The high-entropy carbide ceramic is thermally stable after annealing to up to 1700 ºC in Ar atmosphere without phase transformation or decomposition. It inherits the high elastic modulus and hardness of the binary carbide ceramics. It exhibits a much lower thermal diffusivity and conductivity than the binary carbides, which may result from the significant phonon scattering at its distorted anion sublattice. Irradiation damage has been evaluated by conducting heavy ion irradiation experiments. Microstructure changes, including the phase transformation, irradiation defect clusters, and helium bubbles, have been characterized using transmission electron microscopy as a function of temperature and irradiation dose. |