摘要
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.
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-0516
the National Natural Science Foundation of China via grant No.12175013
J.P.Song acknowledges funding support from the National Magnetic Confinement Fusion Program of China via Grant No.2018YFE031210.
