Al-Cu-Y alloys were prepared by molten salt electrolysis in fluoride-oxide system composed of electrolyte（Na3 AlF6-AlF3-LiF-MgF2） and oxide（Al2 O3-CuO-Y2 O3）. Cathodic reduction process of Al2 O3,CuO and Y2 O3 wer...Al-Cu-Y alloys were prepared by molten salt electrolysis in fluoride-oxide system composed of electrolyte（Na3 AlF6-AlF3-LiF-MgF2） and oxide（Al2 O3-CuO-Y2 O3）. Cathodic reduction process of Al2 O3,CuO and Y2 O3 were analyzed by cyclic voltammetry and chronoamperometry. Components and phase composition of alloy samples prepared by potentiostatic electrolysis were characterized by scanning electron microscopy and energy dispersive spectroscopy. The results show that the Al-Cu-Y alloy can be prepared in the AIF3-NaF-5 wt%LiF-5 wt%MgF2（NaF/AlF3 = 2.2, molecular ratio） eutectic system with mixed oxide（Al2 O3-CuO-Y2 O3） through 2 h at the conditions of a temperature of 1208 K, cell voltage3.0 V, cathode current density 0.7 A/cm^2. Al（Ⅲ） and Cu（Ⅱ） ions can be reduced to zero valence Al（0） and Cu（0） directly on carbonaceous electrode surface by instantaneous nucleation, respectively, the reduction process is controlled by diffusion. The reduction potential of Y（Ⅲ） ions is close to the active ions of fluoride melts, but strengthened phase AI3 Y can be formed through electrochemical reduction and alloyed process with active Al（Ⅲ） and Cu（Ⅱ） ions, meanwhile, the Al2 Cu and Al3 Y phases are distributed at the grain boundary of Al matrix.展开更多
Photostimulated luminescence (PSL) phenomenon was observed in a fluoride-oxide glass ceramics doped with Eu 2+. When the UV light irradiated glass ceramic was stimulated by a longer wavelength light, PSL at 447 nm due...Photostimulated luminescence (PSL) phenomenon was observed in a fluoride-oxide glass ceramics doped with Eu 2+. When the UV light irradiated glass ceramic was stimulated by a longer wavelength light, PSL at 447 nm due to the 5d-4f transition of Eu 2+ was observed. The PSl excitation band peaking at 543 nm is due to the electron trap centers which are located either in the Eu 2+-doped crystallites or in the glass; where exactly they are located in is not yet known. The optical storage properties of this kind of glass ceramic were also studied. By comparing with the investigations on PSL phosphor Eu 2+ doped alkali halides, PSL mechanism in glass ceramics which is still an open question and has to be investigated in further experiments was explained.展开更多
The electrochemical behaviour of Y￣(3+) and Ba￣(2+) on platinum and copper electrode in molten YF_3(70 wt% )-NaF (20 wt%)-CaF_2(10 wt%) has been studied by means of cyclic voltammetry. discharge curve and so on. Th...The electrochemical behaviour of Y￣(3+) and Ba￣(2+) on platinum and copper electrode in molten YF_3(70 wt% )-NaF (20 wt%)-CaF_2(10 wt%) has been studied by means of cyclic voltammetry. discharge curve and so on. The Y-Ba-Cu alloy is obtained by fused salt electrolysis with molten YF_3-NaF-CaF_2 as electrolyte and Y_2O_3 and BaO as raw materials. Graphite cell acted as an anode and copper rod as consumable cathode. The molten bath temperature was 1193 K. Cathode current density was 20 A/cm￣2. The contents of yttrium, barium and copper in alloy were about 20wt%, 9 wt% and 71 wt% respectively. Yttrium recovery efficiency was 90 wt%. The current efficiency was 70%～80 %.展开更多
基金Project supported by the National Natural Science Foundation of China(51564015)
文摘Al-Cu-Y alloys were prepared by molten salt electrolysis in fluoride-oxide system composed of electrolyte（Na3 AlF6-AlF3-LiF-MgF2） and oxide（Al2 O3-CuO-Y2 O3）. Cathodic reduction process of Al2 O3,CuO and Y2 O3 were analyzed by cyclic voltammetry and chronoamperometry. Components and phase composition of alloy samples prepared by potentiostatic electrolysis were characterized by scanning electron microscopy and energy dispersive spectroscopy. The results show that the Al-Cu-Y alloy can be prepared in the AIF3-NaF-5 wt%LiF-5 wt%MgF2（NaF/AlF3 = 2.2, molecular ratio） eutectic system with mixed oxide（Al2 O3-CuO-Y2 O3） through 2 h at the conditions of a temperature of 1208 K, cell voltage3.0 V, cathode current density 0.7 A/cm^2. Al（Ⅲ） and Cu（Ⅱ） ions can be reduced to zero valence Al（0） and Cu（0） directly on carbonaceous electrode surface by instantaneous nucleation, respectively, the reduction process is controlled by diffusion. The reduction potential of Y（Ⅲ） ions is close to the active ions of fluoride melts, but strengthened phase AI3 Y can be formed through electrochemical reduction and alloyed process with active Al（Ⅲ） and Cu（Ⅱ） ions, meanwhile, the Al2 Cu and Al3 Y phases are distributed at the grain boundary of Al matrix.
文摘Photostimulated luminescence (PSL) phenomenon was observed in a fluoride-oxide glass ceramics doped with Eu 2+. When the UV light irradiated glass ceramic was stimulated by a longer wavelength light, PSL at 447 nm due to the 5d-4f transition of Eu 2+ was observed. The PSl excitation band peaking at 543 nm is due to the electron trap centers which are located either in the Eu 2+-doped crystallites or in the glass; where exactly they are located in is not yet known. The optical storage properties of this kind of glass ceramic were also studied. By comparing with the investigations on PSL phosphor Eu 2+ doped alkali halides, PSL mechanism in glass ceramics which is still an open question and has to be investigated in further experiments was explained.
文摘The electrochemical behaviour of Y￣(3+) and Ba￣(2+) on platinum and copper electrode in molten YF_3(70 wt% )-NaF (20 wt%)-CaF_2(10 wt%) has been studied by means of cyclic voltammetry. discharge curve and so on. The Y-Ba-Cu alloy is obtained by fused salt electrolysis with molten YF_3-NaF-CaF_2 as electrolyte and Y_2O_3 and BaO as raw materials. Graphite cell acted as an anode and copper rod as consumable cathode. The molten bath temperature was 1193 K. Cathode current density was 20 A/cm￣2. The contents of yttrium, barium and copper in alloy were about 20wt%, 9 wt% and 71 wt% respectively. Yttrium recovery efficiency was 90 wt%. The current efficiency was 70%～80 %.
