This paper reviews the current state of knowledge and advances on the stress-corrosion cracking(SCC)of Ti alloys subject to harsh corrosive environments in the deep sea,and presents the knowledge gaps and future direc...This paper reviews the current state of knowledge and advances on the stress-corrosion cracking(SCC)of Ti alloys subject to harsh corrosive environments in the deep sea,and presents the knowledge gaps and future directions.A comprehensive review of classifications and applications of Ti alloys for deep-sea engineering indicates that the near-αandα+βTi alloys with high strength and great weldability are the primary selection for deep-sea equipment.The role of residual stress,microstructure types,alloying elements and corrosive environmental factors on SCC performance of Ti alloys are also summarised.It is revealed that the Ti alloys with Widmanstatten structure show the lowest SCC susceptibility,and alloying of Nb,Mo and Al elements plays a positive role in the boost corrosion resistance of passive film.Syn-ergistic effects of environmental deep-sea factors include high hydrostatic pressure,low dissolved oxy-gen content,low temperature and decreasing pH levels intensify the SCC of Ti alloys by inducing local dissolution of the passive film and facilitating hydrogen-induced cracking at crack tip.The study also highlights future research requirements in SCC of Ti alloys in deep sea:including the set-up of unified and suitable methods of in-situ and simulated experiments,modeling and predicting of SCC behaviour in real situations,and exploring practical protective strategies specifically.These findings provide a refer-ence for further SCC mechanisms research and promote the microstructure optimisation and performance improvement of the advanced Ti alloy-based material systems for deep-sea engineering.展开更多
Zero‐dimensional carbon dots(0D C‐dots)and one‐dimensional sulfide cadmium nanowires(1D CdS NWs)were prepared by microwave and solvothermal methods,respectively.A series of heterogeneous photocatalysts that consist...Zero‐dimensional carbon dots(0D C‐dots)and one‐dimensional sulfide cadmium nanowires(1D CdS NWs)were prepared by microwave and solvothermal methods,respectively.A series of heterogeneous photocatalysts that consisted of 1D CdS NWs that were modified with 0D C‐dots(C‐dots/CdS NWs)were synthesized using chemical deposition methods.The mass fraction of C‐dots to CdS NWs in these photocatalysts was varied.The photocatalysts were characterized using X‐ray diffraction,scanning electron microscopy,transmission electron microscopy,X‐ray photoelectron spectroscopy,and ultraviolet‐visible spectroscopy.Their photocatalytic performance for the spitting of water and the degradation of rhodamine B(RhB)under visible light irradiation were investigated.The photocatalytic performance of the C‐dots/CdS NWs was enhanced when compared with that of the pure CdS NWs,with the 0.4%C‐dots/CdS NWs exhibiting the highest photocatalytic activity for the splitting of water and the degradation of RhB.The enhanced photocatalytic activity was attributed to a higher carrier density because of the heterojunction between the C‐dots and CdS NWs.This heterojunction improved the electronic transmission capacity and promoted efficient separation of photogenerated electrons and holes.展开更多
基金supported by the National Natural Science Foundation of China(Nos.51931008 and 52201090).
文摘This paper reviews the current state of knowledge and advances on the stress-corrosion cracking(SCC)of Ti alloys subject to harsh corrosive environments in the deep sea,and presents the knowledge gaps and future directions.A comprehensive review of classifications and applications of Ti alloys for deep-sea engineering indicates that the near-αandα+βTi alloys with high strength and great weldability are the primary selection for deep-sea equipment.The role of residual stress,microstructure types,alloying elements and corrosive environmental factors on SCC performance of Ti alloys are also summarised.It is revealed that the Ti alloys with Widmanstatten structure show the lowest SCC susceptibility,and alloying of Nb,Mo and Al elements plays a positive role in the boost corrosion resistance of passive film.Syn-ergistic effects of environmental deep-sea factors include high hydrostatic pressure,low dissolved oxy-gen content,low temperature and decreasing pH levels intensify the SCC of Ti alloys by inducing local dissolution of the passive film and facilitating hydrogen-induced cracking at crack tip.The study also highlights future research requirements in SCC of Ti alloys in deep sea:including the set-up of unified and suitable methods of in-situ and simulated experiments,modeling and predicting of SCC behaviour in real situations,and exploring practical protective strategies specifically.These findings provide a refer-ence for further SCC mechanisms research and promote the microstructure optimisation and performance improvement of the advanced Ti alloy-based material systems for deep-sea engineering.
基金financially supported by the Research Fund of State Key Laboratory for Marine Corrosion and Protection of Luoyang Ship Material Research Institute(LSMRI)(KF160413)the National Natural Science Foundation of China(21301161,41376126)~~
文摘Zero‐dimensional carbon dots(0D C‐dots)and one‐dimensional sulfide cadmium nanowires(1D CdS NWs)were prepared by microwave and solvothermal methods,respectively.A series of heterogeneous photocatalysts that consisted of 1D CdS NWs that were modified with 0D C‐dots(C‐dots/CdS NWs)were synthesized using chemical deposition methods.The mass fraction of C‐dots to CdS NWs in these photocatalysts was varied.The photocatalysts were characterized using X‐ray diffraction,scanning electron microscopy,transmission electron microscopy,X‐ray photoelectron spectroscopy,and ultraviolet‐visible spectroscopy.Their photocatalytic performance for the spitting of water and the degradation of rhodamine B(RhB)under visible light irradiation were investigated.The photocatalytic performance of the C‐dots/CdS NWs was enhanced when compared with that of the pure CdS NWs,with the 0.4%C‐dots/CdS NWs exhibiting the highest photocatalytic activity for the splitting of water and the degradation of RhB.The enhanced photocatalytic activity was attributed to a higher carrier density because of the heterojunction between the C‐dots and CdS NWs.This heterojunction improved the electronic transmission capacity and promoted efficient separation of photogenerated electrons and holes.
