A novel hybrid material consisted of carbon covered Fe_(3)O_(4)nanoparticles and MoS_(2)nanoflower(FCM)was designed and prepared by micelle-assisted hydrothermal methods.Multiple techniques,including X-Ray diffraction...A novel hybrid material consisted of carbon covered Fe_(3)O_(4)nanoparticles and MoS_(2)nanoflower(FCM)was designed and prepared by micelle-assisted hydrothermal methods.Multiple techniques,including X-Ray diffraction(XRD),high-resolution transmission electron microscopy(HRTEM)and X-ray photoelectron spectroscopy(XPS)were employed to characterize it.The results show that FCM has a flower-like morphology with a 330 nm Fe_(3)O_(4)core as well as 70 nm highly crystalline MoS_(2)shell.FCM is superparamagnetic with a saturation magnetization of 35 emu g-1.Then hydrocracking of Canadian bitumen residue(CBR)was applied to estimate its catalytic activity.The results show that FCM exhibits superior catalytic hydrocracking activity compared to bulk MoS_(2)and commercial oil-dispersed Mo(CO)6 by the same Mo loading.Further measurement by elemental analysis,XPS and XRD reveals that the MoS_(2)nanoflower with abundant catalytic active sites and covered carbon layer with anti-coke ability donate to the superior upgrading performance.Besides,the catalysts can be easily recovered by the external magnetic field.This work provides a novel kind magnetic nanocatalyst which is potential for slurry-phase hydrocracking applications.■2020,Institute of Process Engineering,Chinese Academy of Sciences.Publishing services by Elsevier B.V.on behalf of KeAi Communications Co.,Ltd.This is an open access article under the CC BY-NC-ND license(http://creativecommons.org/licenses/by-nc-nd/4.0/).展开更多
FeAl composites with 21, 37 and 50 wt pct Fe3AlC0.5 were fabricated by a self-propagating high temperature synthesis （SHS） casting. Phases and microstructures were analyzed by X-ray diffraction （XRD） and scanning ...FeAl composites with 21, 37 and 50 wt pct Fe3AlC0.5 were fabricated by a self-propagating high temperature synthesis （SHS） casting. Phases and microstructures were analyzed by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. Microhardness and bending strength of the composites were measured. The composites with 21 and 50 wt pct Fe3AlC0.5 mainly consisted of FeAl and FesAlC0.5 phases, whereas the composite with 37 wt pct Fe3AlC0.5 was composed of FeAl, Fe3AlC0.5 and graphite phases. The bonding of the reinforcement and the matrix was good. Hardness and bending strength of the composite with 37 wt pct Fe3AlC0.5 was lower than those of the 21 and 50 wt pct composites owing to the presence of the soft graphite phase.展开更多
The mechanical properties of super saturated solid solution Fe60Cu40 alloy has been investigated using compression test. The results show that the grain precipitation and phase transformation occurs during compressive...The mechanical properties of super saturated solid solution Fe60Cu40 alloy has been investigated using compression test. The results show that the grain precipitation and phase transformation occurs during compressive deformation resulting in large work-hardening ability, high strength and large ductility. Our results demonstrate that this novel architecture offers a design pathway towards a new generation of strong materials with large ductility.展开更多
Influence of microstructure on electrochemical behavior of nanocrystalline Fe88Si12 alloy has been investigated in 3.5 wt% NaCl solution. The results show that FFe88Si12 alloy with optimal corrosion resistance is comp...Influence of microstructure on electrochemical behavior of nanocrystalline Fe88Si12 alloy has been investigated in 3.5 wt% NaCl solution. The results show that FFe88Si12 alloy with optimal corrosion resistance is composite of ordered Fe3Si and disordered Fe(Si) phases and grain size of 40 nm. Because the ordered Fe3Si structure is beneficial to form SiO2 film, which possesses good corrosion resistance compared with the Fe2O3 film from disordered Fe(Si). Moreover, although the decreased grain size is conducive to form preservative, as the grain size decreases to 10 nm, the grain boundary increases to above 30 vol%, which is the active sites for corrosion attack.展开更多
An ultrafine grained Fe-40Al intermetallic compound is fabricated by a self- propagating high temperature synthesis （SHS） casting. The XRD result shows that the Fe-40Al intermetallic compound consists of the B2 FeAl...An ultrafine grained Fe-40Al intermetallic compound is fabricated by a self- propagating high temperature synthesis （SHS） casting. The XRD result shows that the Fe-40Al intermetallic compound consists of the B2 FeAl phase. The Fe-40Al intermetallic compound presents ultrafine grain size in the range of 100-600 rim, leading from the high nucleation rate and the low growth rate. The Fe-40Al intermetallic compound exhibits high hardness （3.4 GPa） and high bending strength （830 MPa） and high compressive strength （2700 MPa）, which originate from the ultrafine-structure in the material. The effect of the load on dry-sliding wear rate of the material against AISI52100 steel was investigated. The wear rate increases with the increase of normal load. The dominated weax mechanism is microfracture.展开更多
基金financial support:The National Natural Science Foundation of China(21922814,21921005,21676273,21961160745,U1507203,31961133019)the Youth Innovation Promotion Association,CAS(Grant Nos.2016043)+1 种基金Beijing Natural Science Foundation(20194086)China Petroleum Enterprise Cooperation Project(PRIKY17094)。
文摘A novel hybrid material consisted of carbon covered Fe_(3)O_(4)nanoparticles and MoS_(2)nanoflower(FCM)was designed and prepared by micelle-assisted hydrothermal methods.Multiple techniques,including X-Ray diffraction(XRD),high-resolution transmission electron microscopy(HRTEM)and X-ray photoelectron spectroscopy(XPS)were employed to characterize it.The results show that FCM has a flower-like morphology with a 330 nm Fe_(3)O_(4)core as well as 70 nm highly crystalline MoS_(2)shell.FCM is superparamagnetic with a saturation magnetization of 35 emu g-1.Then hydrocracking of Canadian bitumen residue(CBR)was applied to estimate its catalytic activity.The results show that FCM exhibits superior catalytic hydrocracking activity compared to bulk MoS_(2)and commercial oil-dispersed Mo(CO)6 by the same Mo loading.Further measurement by elemental analysis,XPS and XRD reveals that the MoS_(2)nanoflower with abundant catalytic active sites and covered carbon layer with anti-coke ability donate to the superior upgrading performance.Besides,the catalysts can be easily recovered by the external magnetic field.This work provides a novel kind magnetic nanocatalyst which is potential for slurry-phase hydrocracking applications.■2020,Institute of Process Engineering,Chinese Academy of Sciences.Publishing services by Elsevier B.V.on behalf of KeAi Communications Co.,Ltd.This is an open access article under the CC BY-NC-ND license(http://creativecommons.org/licenses/by-nc-nd/4.0/).
基金the National Natural Science Foundation of China(No.50801064)the National 973 Project of China(NO.2007CB607601)the National 863 Project of China(No.2006AA03A219)for financial support.
文摘FeAl composites with 21, 37 and 50 wt pct Fe3AlC0.5 were fabricated by a self-propagating high temperature synthesis （SHS） casting. Phases and microstructures were analyzed by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. Microhardness and bending strength of the composites were measured. The composites with 21 and 50 wt pct Fe3AlC0.5 mainly consisted of FeAl and FesAlC0.5 phases, whereas the composite with 37 wt pct Fe3AlC0.5 was composed of FeAl, Fe3AlC0.5 and graphite phases. The bonding of the reinforcement and the matrix was good. Hardness and bending strength of the composite with 37 wt pct Fe3AlC0.5 was lower than those of the 21 and 50 wt pct composites owing to the presence of the soft graphite phase.
文摘The mechanical properties of super saturated solid solution Fe60Cu40 alloy has been investigated using compression test. The results show that the grain precipitation and phase transformation occurs during compressive deformation resulting in large work-hardening ability, high strength and large ductility. Our results demonstrate that this novel architecture offers a design pathway towards a new generation of strong materials with large ductility.
文摘Influence of microstructure on electrochemical behavior of nanocrystalline Fe88Si12 alloy has been investigated in 3.5 wt% NaCl solution. The results show that FFe88Si12 alloy with optimal corrosion resistance is composite of ordered Fe3Si and disordered Fe(Si) phases and grain size of 40 nm. Because the ordered Fe3Si structure is beneficial to form SiO2 film, which possesses good corrosion resistance compared with the Fe2O3 film from disordered Fe(Si). Moreover, although the decreased grain size is conducive to form preservative, as the grain size decreases to 10 nm, the grain boundary increases to above 30 vol%, which is the active sites for corrosion attack.
基金supported by the National Natural Science Foundation of China (No50801064)the National Basic Research Program of China(No2007CB607601)
文摘An ultrafine grained Fe-40Al intermetallic compound is fabricated by a self- propagating high temperature synthesis （SHS） casting. The XRD result shows that the Fe-40Al intermetallic compound consists of the B2 FeAl phase. The Fe-40Al intermetallic compound presents ultrafine grain size in the range of 100-600 rim, leading from the high nucleation rate and the low growth rate. The Fe-40Al intermetallic compound exhibits high hardness （3.4 GPa） and high bending strength （830 MPa） and high compressive strength （2700 MPa）, which originate from the ultrafine-structure in the material. The effect of the load on dry-sliding wear rate of the material against AISI52100 steel was investigated. The wear rate increases with the increase of normal load. The dominated weax mechanism is microfracture.
