The structure of the quaternary Al?(2?4)wt.%Ca?Ni?La system near the aluminum corner has been studied using computational analysis in the Thermo-Calc program and experimental studies(electron microscopy,microprobe ana...The structure of the quaternary Al?(2?4)wt.%Ca?Ni?La system near the aluminum corner has been studied using computational analysis in the Thermo-Calc program and experimental studies(electron microscopy,microprobe analysis and X-ray diffraction).Based on the phase equilibria data obtained,the experimental projection of the liquidus surface and solid state phase-field distribution of the Al?Ca?Ni?La system have been proposed.Microstructure studies reveal that the alloys with the 2?4 wt.%Ca,2?4 wt.%Ni and 1?3 wt.%La ranges have an ultra-fine hypoeutectic structure with 30%volume fraction of eutectic intermetallics,which allows one to classify these alloys as natural Al-matrix composites.The ultra-fine eutectic structure produces significant strengthening,the magnitude of which can be well described using the modified Orowan looping mechanism model.Small additives of Zr and Sc(0.2 and 0.1 wt.%,respectively)lead to significant strengthening(by^25%)due to the formation of L12 type phase(Al3(Zr,Sc))nanoparticles during annealing of the alloy at 350?400℃.Due to the high volume fraction of eutectic intermetallics,the new alloys have low coefficients of thermal expansion and high thermal stability of the structure and mechanical properties.展开更多
As a newly developing superplastic aluminum alloy, Al Ca alloy has been widely used in industry, however the technology for preparing Al Ca master alloy and its influencing factors need to be further studied. Therefor...As a newly developing superplastic aluminum alloy, Al Ca alloy has been widely used in industry, however the technology for preparing Al Ca master alloy and its influencing factors need to be further studied. Therefore the Al Ca master alloy was prepared by using liquid aluminum cathode and a mixture of 80%CaCl 2 18%KCl 2%CaF 2 as the molten salt electrolysis in a laboratory electrolyte cell; the effects of electrolysis temperature, cathodic current density and electrolytic duration on current efficiency and Ca content of Al Ca alloy as well were studied. Through laboratory experiments, the parameters for smooth electrolytic reaction were proposed. The proper electrolysis technology is as follows: with the 80%CaCl 2 18%KCl 2%CaF 2 electrolyte, the electrolytic temperature is 973 K and the cathodic current density is 0.8 A/cm 2, the electrolysis can go on smoothly and a calcium content of 17.5%(mass fraction) can be obtained. With the increase of electrolysis duration, the calcium content in the alloy increases whereas the current efficiency decreases.展开更多
Salt lake brine was reacted with activated aluminum-based alloys and lithium was precipitated.The effects of aluminum-based alloys on precipitating lithium were investigated and the reasonable alloy used to extract li...Salt lake brine was reacted with activated aluminum-based alloys and lithium was precipitated.The effects of aluminum-based alloys on precipitating lithium were investigated and the reasonable alloy used to extract lithium from brine was obtained.The effects of the mole ratio of Al to Li and Ca content of Al-Ca alloy,the initial concentration of lithiumion ion in solution,reaction temperature and reaction time on the adsorption rate of lithium were studied,and the optimized process parameters were determined.The results show that the mole ratio of Al to Li and Ca content of Al-Ca alloy and reaction temperature have great influences on the precipitation rate of lithium.The precipitation rate of lithium reaches 94.6% under the optimal condition,indicating that Al-Ca alloy is suitable for the extraction of lithium from salt lake brine.展开更多
基金financially supported by the Russian Science Foundation(No.20-19-00746)(SEM,DSC,thermodynamic calculations)the federal academic leadership program Priority 2030 of NUST MISIS(DFT,XRD)。
基金financial support of the grant of the Russian Science Foundation(Project No.18-79-00345)(preparation of alloys,electron microscopy(SEM,EMPA,TEM),tensile tests)Ministry of Science and Higher Education of the Russian Federation in the framework of Increase Competitiveness Program of MISiS(No.P02-2017-2-10)(thermodynamic calculations,dilatometry,DSC and XRD).
文摘The structure of the quaternary Al?(2?4)wt.%Ca?Ni?La system near the aluminum corner has been studied using computational analysis in the Thermo-Calc program and experimental studies(electron microscopy,microprobe analysis and X-ray diffraction).Based on the phase equilibria data obtained,the experimental projection of the liquidus surface and solid state phase-field distribution of the Al?Ca?Ni?La system have been proposed.Microstructure studies reveal that the alloys with the 2?4 wt.%Ca,2?4 wt.%Ni and 1?3 wt.%La ranges have an ultra-fine hypoeutectic structure with 30%volume fraction of eutectic intermetallics,which allows one to classify these alloys as natural Al-matrix composites.The ultra-fine eutectic structure produces significant strengthening,the magnitude of which can be well described using the modified Orowan looping mechanism model.Small additives of Zr and Sc(0.2 and 0.1 wt.%,respectively)lead to significant strengthening(by^25%)due to the formation of L12 type phase(Al3(Zr,Sc))nanoparticles during annealing of the alloy at 350?400℃.Due to the high volume fraction of eutectic intermetallics,the new alloys have low coefficients of thermal expansion and high thermal stability of the structure and mechanical properties.
文摘As a newly developing superplastic aluminum alloy, Al Ca alloy has been widely used in industry, however the technology for preparing Al Ca master alloy and its influencing factors need to be further studied. Therefore the Al Ca master alloy was prepared by using liquid aluminum cathode and a mixture of 80%CaCl 2 18%KCl 2%CaF 2 as the molten salt electrolysis in a laboratory electrolyte cell; the effects of electrolysis temperature, cathodic current density and electrolytic duration on current efficiency and Ca content of Al Ca alloy as well were studied. Through laboratory experiments, the parameters for smooth electrolytic reaction were proposed. The proper electrolysis technology is as follows: with the 80%CaCl 2 18%KCl 2%CaF 2 electrolyte, the electrolytic temperature is 973 K and the cathodic current density is 0.8 A/cm 2, the electrolysis can go on smoothly and a calcium content of 17.5%(mass fraction) can be obtained. With the increase of electrolysis duration, the calcium content in the alloy increases whereas the current efficiency decreases.
基金Project(U1407137)supported by the National Natural Science Foundation of China
文摘Salt lake brine was reacted with activated aluminum-based alloys and lithium was precipitated.The effects of aluminum-based alloys on precipitating lithium were investigated and the reasonable alloy used to extract lithium from brine was obtained.The effects of the mole ratio of Al to Li and Ca content of Al-Ca alloy,the initial concentration of lithiumion ion in solution,reaction temperature and reaction time on the adsorption rate of lithium were studied,and the optimized process parameters were determined.The results show that the mole ratio of Al to Li and Ca content of Al-Ca alloy and reaction temperature have great influences on the precipitation rate of lithium.The precipitation rate of lithium reaches 94.6% under the optimal condition,indicating that Al-Ca alloy is suitable for the extraction of lithium from salt lake brine.
