Synergistic effects of alloying elements and primary knock-on atoms on irradiation damage in Zr-Nb-Ti ternary alloys

Zirconium alloys, widely used in PWR fuel cladding due to their low neutron absorption and radiation resistance, face challenges in understanding alloying effects on irradiation damage. This study employs Molecular Dynamics (MD) to investigate defect evolution in Zr-Nb-Ti alloys under irradiation. Results show that increasing Nb content significantly amplifies defects, with Nb as a PKA generating the highest defect density in the shortest time, while Ti as a PKA produces the least defects with the longest peak time. At 10 keV, Ti’s peak time is approximately 6.38 times longer than that of Nb and 1.89 times longer than that of Zr. Increasing Ti content while maintaining alloy strength enhances its probability as a PKA, improving radiation resistance. These findings provide theoretical insights for optimizing zirconium alloy irradiation resistance and offer guidance for nuclear cladding material design.