Microstructure and mechanical properties of titanium aluminum carbides neutron irradiated at 400-700 °C

This work reports the first mechanical properties of Ti3AlC2-Ti5Al2C3 materials neutron irradiated at ∼400, 630 and 700 °C at a fluence of 2 × 1025 n m−2 (E > 0.1 MeV) or a displacement dose of ∼2 dpa. After irradiation at ∼400 °C, anisotropic swelling and loss of 90% flexural strength was observed. After irradiation at ∼630-700 °C, properties were unchanged. Microcracking and kinking-delamination had occurred during irradiation at ∼630-700 °C. Further examination showed no cavities in Ti3AlC2 after irradiation at ∼630 °C, and MX and A lamellae were preserved. However, disturbance of (0004) reflections corresponding to M-A layers was observed, and the number density of line/planar defects was ∼1023 m−3 of size 5-10 nm. HAADF identified these defects as antisite TiAl atoms. Ti3AlC2-Ti5Al2C3 shows abrupt dynamic recovery of A-layers from ∼630 °C, but a higher temperature appears necessary for full recovery.