Neutron and heavy-ion irradiation of tungsten produces nanometer-size vacancy voids,gas-filled bubbles and dislocation loops.These defect features can a ect mechanical properties and the impact can be quite significan...Neutron and heavy-ion irradiation of tungsten produces nanometer-size vacancy voids,gas-filled bubbles and dislocation loops.These defect features can a ect mechanical properties and the impact can be quite significant because of their high density.Understanding the basic mechanisms of mechanical properties degradation is necessary for predicting radiation e ects.Predictions can be made using discrete dislocation dynamics or/and finite element approaches which,however,need local interaction mechanisms as inputs.Such knowledge can be provided only by atomic-scale modeling.This paper reports the results of an extensive atomic-scale modeling study of the interactions between moving edge dislocations and voids in tungsten.The main focus is on the e ects of the void size and ambient temperature.Critical resolved shear stress was calculated for voids up to 9 nm in diameter.Atomistic results are compared with the theoretical approach and with those obtained earlier for voids in body centered cubic(bcc)iron.An important role of the void surface has been revealed.展开更多
基金financially supported by the Office of Fusion Energy Sciences,U.S.Department of Energy,under contract DE-AC05-00OR22725 with UT-Battelle,LLC
文摘Neutron and heavy-ion irradiation of tungsten produces nanometer-size vacancy voids,gas-filled bubbles and dislocation loops.These defect features can a ect mechanical properties and the impact can be quite significant because of their high density.Understanding the basic mechanisms of mechanical properties degradation is necessary for predicting radiation e ects.Predictions can be made using discrete dislocation dynamics or/and finite element approaches which,however,need local interaction mechanisms as inputs.Such knowledge can be provided only by atomic-scale modeling.This paper reports the results of an extensive atomic-scale modeling study of the interactions between moving edge dislocations and voids in tungsten.The main focus is on the e ects of the void size and ambient temperature.Critical resolved shear stress was calculated for voids up to 9 nm in diameter.Atomistic results are compared with the theoretical approach and with those obtained earlier for voids in body centered cubic(bcc)iron.An important role of the void surface has been revealed.
