We report helium ion irradiation experiments for a new type of dispersion-strengthened NiMo-Y_(2)O_(3)alloy with three different irradiation doses and varying irradiation dose rates at 750℃to evaluate its helium-indu...We report helium ion irradiation experiments for a new type of dispersion-strengthened NiMo-Y_(2)O_(3)alloy with three different irradiation doses and varying irradiation dose rates at 750℃to evaluate its helium-induced damage behavior.Transmission electron microscopy was used to reveal the evolution of helium bubbles after irradiation.The experimental results show that with increasing ion dose,the number density of helium bubbles increases continuously.However,the mean size of helium bubbles first increases and then decreases,mainly due to the varied ion dose rates.The volume fractions of helium bubbles in the three investigated samples after irradiation are 0.15%,0.32%,and 0.27%,which are lower than that of the Hastelloy N alloy(0.58%)after similar irradiation conditions.This indicates that the NiMo-Y_(2)O_(3)alloy exhibits better helium-induced-swelling resistance than the Hastelloy N alloy,highlighting its potential applicability to MSRs,from the perspective of irradiation performance.展开更多
The commercialisation of molten salts reactors(MSRs)is hindered by the lack of structural materials capable of withstanding the corrosive environment therein.To address this problem,we herein prepared1 wt%Y_(2)O_(3)md...The commercialisation of molten salts reactors(MSRs)is hindered by the lack of structural materials capable of withstanding the corrosive environment therein.To address this problem,we herein prepared1 wt%Y_(2)O_(3)mdispersion-strengthened Ni Mo-based alloys using powder metallurgy and evaluated their potential as structural materials for MSRs based on their mechanical properties,He swelling behaviour,and molten salt corrosion resistance.In view of the strengthening provided by homogenously dispersed Y_(2)O_(3)particles,all NiMo-Y_(2)O_(3)samples exhibited ultimate tensile strengths and yield strengths exceeding those of the Hastelloy N alloy,a state-of-the-art structural material for MSRs.Moreover,the volume fraction of He bubbles in the NiMo-Y_(2)O_(3)samples(~0.3%)was lower than that in the Hastelloy N alloy(0.58%),which showed that the introduction of Y_(2)O_(3)nanoparticles effectively inhibited He swelling.All NiMo-Y_(2)O_(3)samples showed excellent resistance to molten salt corrosion(as reflected by the absence of obvious holes therein),thus holding great promise for the development of irradiation-and molten salt corrosion-resistant structural materials for high-temperature MSRs.展开更多
The Au ion-irradiation experiments of GH3535 alloy,a candidate alloy structural material for molten salt reactor,was carried out in this study.Herein,isochronous annealing experiments were conducted from 200 to 850 ℃...The Au ion-irradiation experiments of GH3535 alloy,a candidate alloy structural material for molten salt reactor,was carried out in this study.Herein,isochronous annealing experiments were conducted from 200 to 850 ℃ to clarify the evolution behavior of damage defects with increasing temperature.The coarsening of dislocation loops and formation and dissolution of precipitates with increasing annealing temperature were characterized by transmission electron microscopy.Nanoindentation was performed to measure the variation of hardness caused by irradiation.Additionally,the relationship between irradiation hardening and microstructure evolution was established.This study lays a foundation for the evaluation of irradiation damage properties of GH3535 alloy at different annealing temperatures.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.12022515,11975304,and 91126012)the Youth Innovation Promotion Association,CAS(Grant No.202063)。
文摘We report helium ion irradiation experiments for a new type of dispersion-strengthened NiMo-Y_(2)O_(3)alloy with three different irradiation doses and varying irradiation dose rates at 750℃to evaluate its helium-induced damage behavior.Transmission electron microscopy was used to reveal the evolution of helium bubbles after irradiation.The experimental results show that with increasing ion dose,the number density of helium bubbles increases continuously.However,the mean size of helium bubbles first increases and then decreases,mainly due to the varied ion dose rates.The volume fractions of helium bubbles in the three investigated samples after irradiation are 0.15%,0.32%,and 0.27%,which are lower than that of the Hastelloy N alloy(0.58%)after similar irradiation conditions.This indicates that the NiMo-Y_(2)O_(3)alloy exhibits better helium-induced-swelling resistance than the Hastelloy N alloy,highlighting its potential applicability to MSRs,from the perspective of irradiation performance.
基金supported by the National Natural Science Foundation of China(Grant Nos.11975304,12022515,11805261,11805256)Youth Innovation Promotion Association,Chinese Academy of Sciences(Grant No.Y202063)。
文摘The commercialisation of molten salts reactors(MSRs)is hindered by the lack of structural materials capable of withstanding the corrosive environment therein.To address this problem,we herein prepared1 wt%Y_(2)O_(3)mdispersion-strengthened Ni Mo-based alloys using powder metallurgy and evaluated their potential as structural materials for MSRs based on their mechanical properties,He swelling behaviour,and molten salt corrosion resistance.In view of the strengthening provided by homogenously dispersed Y_(2)O_(3)particles,all NiMo-Y_(2)O_(3)samples exhibited ultimate tensile strengths and yield strengths exceeding those of the Hastelloy N alloy,a state-of-the-art structural material for MSRs.Moreover,the volume fraction of He bubbles in the NiMo-Y_(2)O_(3)samples(~0.3%)was lower than that in the Hastelloy N alloy(0.58%),which showed that the introduction of Y_(2)O_(3)nanoparticles effectively inhibited He swelling.All NiMo-Y_(2)O_(3)samples showed excellent resistance to molten salt corrosion(as reflected by the absence of obvious holes therein),thus holding great promise for the development of irradiation-and molten salt corrosion-resistant structural materials for high-temperature MSRs.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.12022515 and 11975304)the Youth Innovation Promotion Association,Chinese Academy of Sciences(Grant No.Y202063)。
文摘The Au ion-irradiation experiments of GH3535 alloy,a candidate alloy structural material for molten salt reactor,was carried out in this study.Herein,isochronous annealing experiments were conducted from 200 to 850 ℃ to clarify the evolution behavior of damage defects with increasing temperature.The coarsening of dislocation loops and formation and dissolution of precipitates with increasing annealing temperature were characterized by transmission electron microscopy.Nanoindentation was performed to measure the variation of hardness caused by irradiation.Additionally,the relationship between irradiation hardening and microstructure evolution was established.This study lays a foundation for the evaluation of irradiation damage properties of GH3535 alloy at different annealing temperatures.
