Fe-10 at.%Cr alloy was implanted with hydrogen ions at room temperature, followed by annealing at high temperatures.The annealing process made the defects develop into large dislocation loops. The nature of the disloc...Fe-10 at.%Cr alloy was implanted with hydrogen ions at room temperature, followed by annealing at high temperatures.The annealing process made the defects develop into large dislocation loops. The nature of the dislocation loops formed after annealing was studied by the evolution of loops under in situ electron irradiation in high-voltage electron microscope.It indicated that only interstitial-type loops were observed when annealed at 550 °C and below, but vacancy-type loops started to form at the temperature higher than 600 °C. According to the previous study of our group, the presence of chromium element made the formation temperature of vacancy-type loops higher than that in pure iron. The effect of alloying elements on the formation temperature of the vacancy-type loops was discussed.展开更多
Samples of ultra-high-purity tungsten prepared using chemical vapour deposition(CVD)technique were irradiated with neutrons at temperatures T_(irr)=373-483 K(stage Ⅱ of defect recovery)and T_(irr)=573-673 K(stage Ⅲ)...Samples of ultra-high-purity tungsten prepared using chemical vapour deposition(CVD)technique were irradiated with neutrons at temperatures T_(irr)=373-483 K(stage Ⅱ of defect recovery)and T_(irr)=573-673 K(stage Ⅲ)up to 0.15 displacements per atom(dpa)in the Belgian reactor(BR2).The study of the microstructure of neutron-damaged samples using transmission electron microscopy(TEM)revealed visible defects with a predominance of dislocation loops.With an increase in the neutron irradiation temperature,the spatial distribution of the loops acquired pronounced inhomogeneity,and their average size moderately increased.Cavities and voids were not observed.Irradiation-induced hardening was found and a linear correlation was obtained between Vickers microhardness and nanohardness for undamaged and neutron-irradiated CVD-W samples.Irradiation of tungsten with neutrons led to a significant increase in the retention of deuterium,which accumulated mainly in vacancy-type traps.Furthermore,the influence of the columnar grain structure in low-dose neutron-irradiated tungsten seemed to be non-trivial upon deuterium retention.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 51471026)
文摘Fe-10 at.%Cr alloy was implanted with hydrogen ions at room temperature, followed by annealing at high temperatures.The annealing process made the defects develop into large dislocation loops. The nature of the dislocation loops formed after annealing was studied by the evolution of loops under in situ electron irradiation in high-voltage electron microscope.It indicated that only interstitial-type loops were observed when annealed at 550 °C and below, but vacancy-type loops started to form at the temperature higher than 600 °C. According to the previous study of our group, the presence of chromium element made the formation temperature of vacancy-type loops higher than that in pure iron. The effect of alloying elements on the formation temperature of the vacancy-type loops was discussed.
基金Neutron irradiations at BR2 in SCK/CEN were carried out in the framework of MICADO project.Hot-lab experiments were conducted at the International Research Centre for Nuclear Materials Science(Oarai site),Institute for Materials Research(IMR),Tohoku University.All authors wish to thank IMR staffs Mr.K.Suzuki and T.Maniwa for their kind assistance.X.Yi acknowledges funding support from the Global Institute for Materials Research Tohoku(GIMRT)program via proposals No.19M0504,20M0502 and 202012-IRKMA-0516the National Natural Science Foundation of China via grant No.12175013J.P.Song acknowledges funding support from the National Magnetic Confinement Fusion Program of China via Grant No.2018YFE031210.
文摘Samples of ultra-high-purity tungsten prepared using chemical vapour deposition(CVD)technique were irradiated with neutrons at temperatures T_(irr)=373-483 K(stage Ⅱ of defect recovery)and T_(irr)=573-673 K(stage Ⅲ)up to 0.15 displacements per atom(dpa)in the Belgian reactor(BR2).The study of the microstructure of neutron-damaged samples using transmission electron microscopy(TEM)revealed visible defects with a predominance of dislocation loops.With an increase in the neutron irradiation temperature,the spatial distribution of the loops acquired pronounced inhomogeneity,and their average size moderately increased.Cavities and voids were not observed.Irradiation-induced hardening was found and a linear correlation was obtained between Vickers microhardness and nanohardness for undamaged and neutron-irradiated CVD-W samples.Irradiation of tungsten with neutrons led to a significant increase in the retention of deuterium,which accumulated mainly in vacancy-type traps.Furthermore,the influence of the columnar grain structure in low-dose neutron-irradiated tungsten seemed to be non-trivial upon deuterium retention.
