Microstructural damage evolution of (WTiVNbTa)C5 high-entropy carbide ceramics induced by self-ions irradiation

High-entropy carbide ceramics (WTiVNbTa)C5 were prepared by spark plasma sintering and irradiated with 1.0 MeV C-ions at room temperature (RT) and 650 ℃. Irradiation induced damage evolution and mechanical properties change were investigated. GIXRD and TEM results showed that the irradiation led to lattice expansion and micro-strain formation in the samples, which originated from the irradiation induced defects. The black-dot defects dominated in the damaged microstructure at fluence of 1E16 ions/cm2 and transformed into dislocation loops and networks with the fluence increased at RT. Reduction of irradiation damage and formation of defect denuded zone were observed at 650 ℃. No amorphization or void formation were observed for all samples after irradiation. The irradiation hardening was most severe at fluence of 1E16 ions/cm2 and recovered at higher fluence or temperature, while the elastic modulus monotonically decreased. The correlation between microstructural evolution and mechanical properties response was discussed.