Thermal effects in ion irradiated Ti2AlC and Ti3SiC2

Structural materials in nuclear systems endure a harsh environment, like high temperature, high stress and intense radiation fluxes. MAX phases have been suggested for advanced nuclear reactor applications due to their excellent irradiation tolerance, especially in high temperature irradiation. To better understand the mechanisms of irradiation tolerance of MAX phases and the evolution of defects in high temperature irradiation, herein, we irradiated Ti2AlC and Ti3SiC2 with 3 MeV Au ions at 25 degrees C, 360 degrees C and 700 degrees C to a dose of 1.5 x 10(16) cm(-2), and then thermal annealing at 360 degrees C and 700 degrees C were performed for samples irradiated at room temperature to study the defect kinetics. Raman spectrum, GIXRD and TEM were used to characterize microstructural evolution. Our results show that high temperature irradiation causes less damage than room temperature irradiation does in both materials. Fewer defects were produced in Ti3SiC2 than that in Ti2AlC during high temperature irradiation. And Ti2AlC has a higher defect recovery efficiency than Ti3SiC2 when annealed at high temperature.