Enhancing radiation tolerance of Ti2AlN through texture orientation: controlling defect mobility and providing diffusion pathways

• Special textured Ti 2 AlN effectively reduces surface cracking after irradiation. • Texture orientation has a great impact on the transformation of defects. • Microscopic defect behavior in irradiated Ti 2 AlN was analyzed by DFT and MD. • The irradiation mechanism of the textured Ti 2 AlN was unveiled. MAX phase materials exhibit excellent radiation resistance and corrosion resistance. However, at 500°C, Al-based MAX phases exhibit surface cracking caused by irradiation-induced swelling, significantly affecting their application in irradiated environments. In this study, changing the texture orientation of irradiated Ti 2 AlN, the effects of different MAX phase texture orientations on defect evolution and irradiation resistance were investigated. The texture orientation was altered by exposing different surfaces. The results showed that the textured side surface dominated by ( 11 2 ¯ 0 ) and ( 10 1 ¯ 0 ) exhibited less surface cracking than the (0001)-oriented textured top surface after irradiation. Microscopic characterization and theoretical calculations were subsequently performed to determine the underlying microstructural factors. The findings revealed that the textured top surface exhibited nitrogen enrichment and the formation of nano-twins at the maximum damage depth, resulting in uneven defect distribution and internal stress, causing surface cracking. By contrast, the textured side surface provided diffusion pathways parallel to the irradiation direction, dispersing defects throughout the grain, promoting defect recombination, and reducing internal stress. Based on these findings, a defect evolution model was proposed for Ti 2 AlN with different texture orientations at 500 °C. These results offer an effective strategy for enhancing the radiation resistance of other MAX phases.