Ti_3(Si,Al)C_2 FOR NUCLEAR APPLICATION: INVESTIGATION OF IRRADIATION EFFECTS INDUCED BY CHARGED PARTICLES

摘要

In the frame of material development for the future nuclear reactors, MAX phases, especially Ti_3SiC_2-based materials have been recently considered as candidate for the core components in Gas Fast Reactors because of good thermal conductivity, neutron transparency and tolerance to damage. Nevertheless, their behaviour under irradiation has never been investigated until now (including the change in the lamellar microstructure and then a possible loss of the damage tolerance properties). In parallel to progressing neutron irradiations, CEA launched in 2006 irradiations with charged particles of high kinetic energy to precise the evolution of several Ti_3SiC_2 grades. In this work, Ti_3(Si,Al)C_2 fabricated by hot-pressing method were irradiated with Kr and Xe ions at 20°C and 500°C. This allowed to explore both the influence of electronic (near surface) and nuclear (implantation zone) interaction in the same experiment. The effect of dose and temperature on the microstructure and hardness was investigated. No change in hardness or microstructure was detected up to 10~(13)ions/cm~2. Higher doses induced hardness increase, but damage tolerance remained. This hardening should be correlated to atomic disorder and cell change highlighted by TEM and XRD. Annealing of the irradiation defects with temperature was highlighted and would start at 300°C. The formation of p-Ti_3(Si,Al)C_2 under irradiation is suggested.