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China Low Activation Martensitic (CLAM) steel is selected as the candidate structural material in Fusion Design Study (FDS) series fusion reactor conceptual designs. The creep property of CLAM steel has been studied in this paper. Creep tests have been carried out at 823 K and 873 K over a stress range of 150–230 MPa. The creep curves showed three creep regimes, primary creep, steady-state creep and tertiary creep. The relationship between minimum creep rate ( ε ̇ min ) and the applied stress ( σ ) could be described by Norton power law, and the stress exponent n was decreased with the increase of the creep temperature. The creep mechanism was analyzed with the fractographes of the rupture specimens which were examined by scanning electron microscopy (SEM). The coarsening of precipitates observed with transmission electron microscope (TEM) indicated the microstructural degradation after creep test. [ABSTRACT FROM AUTHOR]

Abstract: In the design of liquid–metal fusion blankets, Al2O3 ceramic is one of the most promising coating materials. In this study, functionally graded FeAl/Al2O3 coatings were deposited on China Low Activation Martensitic (CLAM) steel substrates with vacuum plasma spraying (VPS) method. The SEM investigation revealed that the adhesion between adjacent layers in the coatings was sound. X-ray diffraction showed that stable alpha alumina dominated in the top alumina layers, while γ-Al2O3 and β-Al2O3 were also detected. The coating/substrate adhesive tensile strength test showed that adhesive strength of graded coatings was about 2.5 times that of duplex FeAl/Al2O3 coatings. Thermal shock resistance test indicated that the graded coatings could tolerate more thermal shock cycles than duplex coatings. [ABSTRACT FROM AUTHOR]

Abstract: Liquid LiPb eutectic is one of the promising candidate tritium breeder materials for fusion reactors. This paper presents the progress in compatibility experiments with liquid LiPb achieved up to now in China for some candidate structural materials. The results showed that CLAM steel had good compatibility with flowing LiPb at 480°C with the velocity of 0.08m/s after 5000h in DRAGON-I loop. On the other hand, after exposed in static LiPb at 700°C for 500h in a SiC crucible, the W and Mo specimens suffered much more weight loss compared with Nb specimen, and a thin reaction product layer was visible on the surface of all the three refractory metals. Preliminary analysis on SiCf/SiC composite specimens indicated that there was no penetration of LiPb and no reaction products on the surface with CVD SiC coating, which showed SiCf/SiC composite were stable and compatible with static LiPb under 700°C after 500h exposure. [Copyright &y& Elsevier]

• A new composite coating of GO-Al 2 O 3 for tritium permeation barrier is prepared by the sol-gel method. • The toughness and deuterium permeation barrier performance of the Al 2 O 3 coating is enhanced by adding the GO nanosheets. • Deuterium permeation reduction factor of the 0.5 wt% GO-Al 2 O 3 composite coating increases about 9 times in comparison with the pure Al 2 O 3 coating. To improve tritium permeation resistance and toughness of Al 2 O 3 coating, a new graphene oxide (GO)-alumina (Al 2 O 3) composite coating as tritium permeation barrier was designed in this paper. GO was added into Al 2 O 3 to prepare the composite coating of GO-Al 2 O 3 by a sol-gel method. The results showed that the deuterium permeation reduction factor (PRF) of 0.5 wt% GO-Al 2 O 3 coating was higher than that of the pure Al 2 O 3 coating at 500 ℃. It was related to the GO nanosheets blocking the diffusion of deuterium atoms in the Al 2 O 3 coating and reducing the permeability. Meanwhile, the toughness of the 0.5 wt% GO-Al 2 O 3 coating was enhanced by about 40 % than the pure Al 2 O 3 coating. The reason can be speculated that GO nanosheets can prevent the cracks propagation in the composite coating of GO-Al 2 O 3. This study could provide a new material of tritium permeation barrier for fusion reactors. [ABSTRACT FROM AUTHOR]