Composition-dependent changes in mechanical property of borosilicate glass induced by electron-ion sequential irradiation

Abstract

Mechanical property and microstructure changes induced by 500-keV He2+ have been investigated in three kinds of 1.2-MeV electron pre-irradiated Na2O-B2O3-SiO2 (labeled as NBS) glasses. The glasses before and after irradiation are analyzed by nanoindentation methods and infrared spectroscopy. The hardness and modulus variation of sequential He-ion irradiation in the electron pre-irradiated NBS1 and NBS2 specimens exhibited damage promotion. On the contrary, a pronounced recovery effect is observed in the behavior of NBS3 glass. Both the hardness and modulus changes are correlated with the microstructure evolution, and the corresponding micro-mechanism is discussed. Moreover, the pre-existing responses induced by electron irradiation differ from the ion irradiation caused, which can alter the damage equilibrium level of modulus on borosilicate glass under He-ion sequential irradiation. This study of electron-ion sequential irradiation effects will provide new insights for understanding the irradiation response of nuclear waste glass matrix under mixed radiation fields.