Study on the Interaction between Stacking Fault Pyramid and Point Defects in Zirconium
Zirconium and its alloys are used as nuclear fuel cladding materials due to their excellent mechanical properties,corrosion resistance,and small thermal neutron absorption cross-sections.When exposed to radiation,a large number of irradiation-induced defects emerge in the zirconium alloy,seriously diminishing its mechanical properties and service life.This study employs molecular dynamics simulations to investigate the interaction between the stacking fault pyramid and point defects(i.e.,interstitial atoms and vacancies)in zirconium.It is found that,at 0 K and 300 K,the stacking fault pyramid exclusively ab-sorbs interstitial atoms;while at 600 K,it absorbs both interstitial atoms and vacancies.To explain this phenomenon,the binding energy of interstitial atoms/vacancies and the stacking fault pyramid is calculat-ed.The results indicate that the binding energy is related to the type/position of point defects:the binding energy of interstitial atoms is much greater than that of vacancies,making interstitial atoms more likely to be absorbed.At the same time,the proximity to the stacking fault pyramid amplifies the binding energy,rendering both point defects more susceptible to absorption.These simulation results provide a new insight into understanding the growth mechanism of irradiation-induced defects in zirconium.
zirconiummolecular dynamics simulationsirradiation-induced point defectsstacking fault pyramid
NETL
NSTL
万方数据
