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Indexed by:期刊论文

Date of Publication:2018-02-01

Journal:JOURNAL OF IRON AND STEEL RESEARCH INTERNATIONAL

Included Journals:SCIE、EI

Volume:25

Issue:2

Page Number:200-206

ISSN No.:1006-706X

Key Words:Tungsten; Damage cascade; Molecular dynamics; Grain boundary; Irradiation-induced defect

Abstract:The effects of two different symmetric tilt grain boundaries (GBs), Sigma 13[001](230) GB and Sigma 17[001](140) GB, on displacement cascade processes in tungsten were investigated using molecular dynamics simulations. By quantifying the number of interstitials and vacancies surviving after irradiation with the kinetic energy of primary knock-on atom energies of 1, 3 and 5 keV, respectively, in these simulations, it is found that the GBs have dual nature for radiation-induced defects: They absorb interstitials while leaving more vacancies to survive in the grains. The net effect is that the number of total surviving defects in the GB system is not always less than that in the single crystal. These defect behaviors are understood by quantitatively analyzing the recovery fraction of irradiation-induced defects, the time to reach steady state and the mobility of vacancies and interstitials. It is also found that the Sigma 17 GB is a more effective sink of radiation- induced point defects than the Sigma 13 GB. One of the main reasons is that the Sigma 17 GB has a higher GB energy.