In order to improve the low ductility of the Mo-Ni alloy,Fe is added and the effects of Ni/Fe mass ratio on the densification behavior,microstructure evolution and mechanical properties of alloy were investigated.The ...In order to improve the low ductility of the Mo-Ni alloy,Fe is added and the effects of Ni/Fe mass ratio on the densification behavior,microstructure evolution and mechanical properties of alloy were investigated.The experimental results show that when iron is added to 95Mo-5Ni alloy,the formation of brittle intermetallic phaseδ-MoNi at the grain boundary is avoided.Meanwhile,the grain growth of Mo is also effectively inhibited in the sintering process.However,the addition of iron reduces the degree of densification of alloy since the activation effect of Ni is superior to that of Fe.From the experimental results,it could be concluded that the maximum hardness and bending strength are achieved by 95Mo-1.5Ni-3.5Fe alloy,which are HV 614 and 741 MPa,respectively.Combined with the analyses of bending fracture mechanism,the improvement relative to Mo-Ni alloy is likely attributed to the inhibition of the brittle phase.展开更多
A novel‐structured Mo‐Cu‐Fe‐O composite was successfully prepared by co‐precipitation and impregnation method.The properties of the as‐prepared samples were determined using X‐ray diffraction,temperature‐progr...A novel‐structured Mo‐Cu‐Fe‐O composite was successfully prepared by co‐precipitation and impregnation method.The properties of the as‐prepared samples were determined using X‐ray diffraction,temperature‐programmed reduction by H2,cyclic voltammetry,and temperature‐programmed desorption by O2.The results showed that Mo6+diffused into the Cu‐Fe‐O crystal lattice and then formed a new crystalline phase of CuMoO4.The Mo‐Cu‐Fe‐O catalyst had redox properties,and its surface contained active sites for oxygen adsorption.In addition,the catalytic activity of the Mo‐Cu‐Fe‐O composite was evaluated by the degradation of Cationic Red GTL,Crystal Violet,and Acid Red in catalytic wet air oxidation(CWAO)at ambient temperature and pressure.The Mo‐Cu‐Fe‐O catalyst showed excellent activity at basic conditions for the degradation of Cationic Red GTL.High removal efficiencies of91.5%and92.8%were achieved for Cationic Red GTL and Crystal Violet,respectively,in wastewater,and the efficiency remained high after seven cycles.However,almost no degradation of Acid Red occurred in the CWAO process.Furthermore,hydroxyl radicals were formed in the CWAO process,which induced the decomposition of the two cationic dyes in wastewater,and the toxicity of their effluents was decreased after degradation.The results indicate that the Mo‐Cu‐Fe‐O composite shows excellent catalytic activity for the treatment of wastewater contaminated with cationic dyes.展开更多
The Huayangchuan ore belt is located in the western segment of Xiaoqinling Orogen in the southern margin of the North China Craton(NCC),and hosts voluminous magmatism and significant U-REE-Mo-Cu-Fe polymetallic minera...The Huayangchuan ore belt is located in the western segment of Xiaoqinling Orogen in the southern margin of the North China Craton(NCC),and hosts voluminous magmatism and significant U-REE-Mo-Cu-Fe polymetallic mineralization.However,geochronological framework of the various mineralization phases in this region is poorly understood.Here,we present new Re-Os isochron ages on magnetite from the Caotan Fe deposit(2 675 ± 410 Ma,MSWD = 0.55),and on pyrite from the Jialu REE deposit(2 127 ± 280 Ma,MSWD = 1.9) and Yuejiawa Cu deposit(418 ± 23 Ma,MSWD =11.5),and Re-Os weighted average model age on pyrite from the Taoyuan Mo-U deposit(235 ± 14 Ma,MSWD = 0.17).These ages,combined with regional geology and mineralization ages from other deposits,suggest that mineralization in the Huayangchuan ore belt lasted from the Neoarchean to the Late Mesozoic.The mineralization corresponds to regional tectono-magmatic events,including the Neoarchean alkali magmatism(REE mineralization),Paleoproterozoic plagioclase-amphibolite emplacement(Fe mineralization),Paleoproterozoic pegmatite magmatism(U mineralization),Paleozoic Shangdan oceanic slab subduction-related arc magmatism(Cu mineralization),Early Mesozoic Paleo-Tethys Ocean subduction-related arc magmatism(Mo-U mineralization),and Late Mesozoic Paleo-Pacific oceanic plate subduction direction change-related Mo(-Pb) mineralization.We proposed that the Huayangchuan ore belt has undergone prolonged metallogenic evolution,and the magmatism and associated mineralization were controlled by regional geodynamic events.展开更多
Mechanical milling behavior of Mo Si Fe powders was investigated using XRD, SEM and TEM techniques. The mixtures of elemental molybdenum (>99%), silicon (>99%) and iron (>98%) powders with a stoichiometry of ...Mechanical milling behavior of Mo Si Fe powders was investigated using XRD, SEM and TEM techniques. The mixtures of elemental molybdenum (>99%), silicon (>99%) and iron (>98%) powders with a stoichiometry of Mo 5- x Fe x Si 3 ( x =0.5, 1, 2) were milled in a planetary mill for up to 195?h. For all three powder mixtures, high energy milling of 60?h led to formation of the Mo(Fe, Si) supersaturated solid solution (Mo ss ); and to a remarkable expansion of the solubility of Fe, Si in molybdenum. The transformation of Mo ss to an amorphous phase was identified after longer time milling. In the milling process, the grain size of Mo (Fe, Si) decreased gradually and the internal stress increased linearly. After 40?h milling, the grain size was reduced to about 11?nm. SEM analysis of milled powders showed that the particle size increased initially with milling time. After 195?h milling, particles exhibited a spherical morphology and the particle size were reduced to about 100?nm.展开更多
基金Project(51734002)supported by the National Natural Science Foundation of China。
文摘In order to improve the low ductility of the Mo-Ni alloy,Fe is added and the effects of Ni/Fe mass ratio on the densification behavior,microstructure evolution and mechanical properties of alloy were investigated.The experimental results show that when iron is added to 95Mo-5Ni alloy,the formation of brittle intermetallic phaseδ-MoNi at the grain boundary is avoided.Meanwhile,the grain growth of Mo is also effectively inhibited in the sintering process.However,the addition of iron reduces the degree of densification of alloy since the activation effect of Ni is superior to that of Fe.From the experimental results,it could be concluded that the maximum hardness and bending strength are achieved by 95Mo-1.5Ni-3.5Fe alloy,which are HV 614 and 741 MPa,respectively.Combined with the analyses of bending fracture mechanism,the improvement relative to Mo-Ni alloy is likely attributed to the inhibition of the brittle phase.
基金supported by the National Natural Science Foundation of China(51678511,51308484)the Natural Science Foundation of Hunan Province(13JJ4049)+3 种基金the Education Department Fund of Hunan Province(14C1094)the Open Fund of Key Laboratory of Mineralogy and Metallogeny in Chinese Academy of Sciences(KLMM20150104)the Major Talent Training Program of Xiangtan University(16PYZ09)the Specialized Research Fund for the Doctoral Program of Xiangtan University(12QDZ18)~~
文摘A novel‐structured Mo‐Cu‐Fe‐O composite was successfully prepared by co‐precipitation and impregnation method.The properties of the as‐prepared samples were determined using X‐ray diffraction,temperature‐programmed reduction by H2,cyclic voltammetry,and temperature‐programmed desorption by O2.The results showed that Mo6+diffused into the Cu‐Fe‐O crystal lattice and then formed a new crystalline phase of CuMoO4.The Mo‐Cu‐Fe‐O catalyst had redox properties,and its surface contained active sites for oxygen adsorption.In addition,the catalytic activity of the Mo‐Cu‐Fe‐O composite was evaluated by the degradation of Cationic Red GTL,Crystal Violet,and Acid Red in catalytic wet air oxidation(CWAO)at ambient temperature and pressure.The Mo‐Cu‐Fe‐O catalyst showed excellent activity at basic conditions for the degradation of Cationic Red GTL.High removal efficiencies of91.5%and92.8%were achieved for Cationic Red GTL and Crystal Violet,respectively,in wastewater,and the efficiency remained high after seven cycles.However,almost no degradation of Acid Red occurred in the CWAO process.Furthermore,hydroxyl radicals were formed in the CWAO process,which induced the decomposition of the two cationic dyes in wastewater,and the toxicity of their effluents was decreased after degradation.The results indicate that the Mo‐Cu‐Fe‐O composite shows excellent catalytic activity for the treatment of wastewater contaminated with cationic dyes.
基金financially supported by the Academician Workstation of Sino Shaanxi Nuclear Industry Group(Nos.ZSH-YS190101 and ZSH-YS180101)Major Project of Basic and Applied Basic Research in Guangdong Province(No.2019B030302013)。
文摘The Huayangchuan ore belt is located in the western segment of Xiaoqinling Orogen in the southern margin of the North China Craton(NCC),and hosts voluminous magmatism and significant U-REE-Mo-Cu-Fe polymetallic mineralization.However,geochronological framework of the various mineralization phases in this region is poorly understood.Here,we present new Re-Os isochron ages on magnetite from the Caotan Fe deposit(2 675 ± 410 Ma,MSWD = 0.55),and on pyrite from the Jialu REE deposit(2 127 ± 280 Ma,MSWD = 1.9) and Yuejiawa Cu deposit(418 ± 23 Ma,MSWD =11.5),and Re-Os weighted average model age on pyrite from the Taoyuan Mo-U deposit(235 ± 14 Ma,MSWD = 0.17).These ages,combined with regional geology and mineralization ages from other deposits,suggest that mineralization in the Huayangchuan ore belt lasted from the Neoarchean to the Late Mesozoic.The mineralization corresponds to regional tectono-magmatic events,including the Neoarchean alkali magmatism(REE mineralization),Paleoproterozoic plagioclase-amphibolite emplacement(Fe mineralization),Paleoproterozoic pegmatite magmatism(U mineralization),Paleozoic Shangdan oceanic slab subduction-related arc magmatism(Cu mineralization),Early Mesozoic Paleo-Tethys Ocean subduction-related arc magmatism(Mo-U mineralization),and Late Mesozoic Paleo-Pacific oceanic plate subduction direction change-related Mo(-Pb) mineralization.We proposed that the Huayangchuan ore belt has undergone prolonged metallogenic evolution,and the magmatism and associated mineralization were controlled by regional geodynamic events.
文摘Mechanical milling behavior of Mo Si Fe powders was investigated using XRD, SEM and TEM techniques. The mixtures of elemental molybdenum (>99%), silicon (>99%) and iron (>98%) powders with a stoichiometry of Mo 5- x Fe x Si 3 ( x =0.5, 1, 2) were milled in a planetary mill for up to 195?h. For all three powder mixtures, high energy milling of 60?h led to formation of the Mo(Fe, Si) supersaturated solid solution (Mo ss ); and to a remarkable expansion of the solubility of Fe, Si in molybdenum. The transformation of Mo ss to an amorphous phase was identified after longer time milling. In the milling process, the grain size of Mo (Fe, Si) decreased gradually and the internal stress increased linearly. After 40?h milling, the grain size was reduced to about 11?nm. SEM analysis of milled powders showed that the particle size increased initially with milling time. After 195?h milling, particles exhibited a spherical morphology and the particle size were reduced to about 100?nm.
