Effects of He-ion irradiation on microstructures of low activation Ti-Ta-V alloy from atomic simulations and irradiation experiments

Abstract

Most conventional titanium alloys contain nuclides with long half-lives, which is not conductive to material recovery after decommissioning. To recover components from post-service reactors safely and effectively, it is necessary to use materials with low activation and rapid induction of radioactive decay. In this work, a low-activation α-titanium alloy Ti-5Ta-1.6 V was prepared and irradiated with 80 keV helium ions to 6.8 dpa at room temperature. The mechanical properties and irradiation swelling properties of Ti-5Ta-1.6 V alloy were mainly investigated. The results showed that compared with the commercially pure titanium alloy (CP-Ti), the mechanical properties of Ti-5Ta-1.6 V were substantially improved. After ion irradiation, the irradiation swelling rate of Ti-5Ta-1.6 V (in mass ratio) was found to be significantly lower than that of CP-Ti by atomic force microscopy (AFM) technology. Molecular dynamic (MD) simulations were used to study the irradiation behavior and cascade collisions process, and the Ti-5Ta-1.6 V produced a small number of stable defects with cluster size and number density, which is consistent with the results of irradiation experiments. The results indicate that Ti-5Ta-1.6 V is expected to be a promising new titanium alloy for nuclear applications, which provides a new idea for the selection and optimization of low-activation and radiation-resistant nuclear materials.