Effect of multiple Ti doping on helium behavior in ZrCo

Abstract Helium can cause segregation of solute atoms in the material, and in turn, the segregated solute atoms will have a great influence on the behavior of helium. Studying the behavior of helium in tritium storage materials is very important for the design of materials with strong helium retention capacity. In this paper, the first-principles method based on density functional theory is used to study the segregation of doped atoms Ti caused by defects (He atoms) in ZrCo system, and the effect of segregated Ti atoms on He behavior. The effect of segregated Ti atoms on the stability of He atoms was explored. The CI-NEB method was used to simulate the variance of the trapping for He atoms by vacancy in the pure and doped systems. Finally, it was found that the number of He atoms trapped by the vacancy is reduced due to the Ti cage. In addition, the Ti cage has a certain pinning effect on He atoms. In short, the segregated Ti inhibits the migration of He and hinders the flow of He to the grain boundaries, thereby suppressing the helium embrittlement effect.