|About this Abstract
||1st World Congress on High Entropy Alloys (HEA 2019)
||High Entropy Alloys 2019
||Outstanding Radiation Resistance of Tungsten-based High Entropy Alloys
||Osman El-Atwani, Stuart Maloy, Arun Devaraj, Damian Sobieraj, Jan Wrobel, Duc Nguyen-Manh, Jonathan Gigax, Enrique Martinez
|On-Site Speaker (Planned)
A novel nanocrystalline W-based refractory high entropy alloy with outstanding radiation resistance has been developed. The alloy was grown as thin films and showed unique 4 nm lamella-like structure. TEM and XRD show an underlying BCC structure with black spots appearing after thermal annealing at elevated temperatures. TEM and APT correlated the black spots with Cr and V precipitation. After heavy ion irradiation, these precipitates evolve to quasi-spherical particles with no sign of irradiation-created dislocation loops even after 8 dpa at either RT or 1073 K. Nanomechanical testing shows a large hardness of 14 GPa in pristine samples, with a slight increase after thermal annealing and almost negligible irradiation hardening. Theoretical modeling based on ab initio methodologies combined with Monte Carlo techniques predicts the formation of Cr and V rich second phase particles and points at equal mobilities of point defects as the origin of the exceptional radiation tolerance.