The microstructures and phase compositions of the as-cast and die-cast Mg-6.02Al-1.03 Sm, Mg-6.05Al-0.98Sm-0.56 Bi and Mg-5.95Al-1.01Sm-0.57 Zn alloys were investigated. Meanwhile, the tensile mechanical and flow prop...The microstructures and phase compositions of the as-cast and die-cast Mg-6.02Al-1.03 Sm, Mg-6.05Al-0.98Sm-0.56 Bi and Mg-5.95Al-1.01Sm-0.57 Zn alloys were investigated. Meanwhile, the tensile mechanical and flow properties were tested. The results show that the as-cast microstructure of Mg-6.02Al-1.03 Sm alloy is composed of δ-Mg matrix, discontinuous δ-Mg17Al12 phase and small block Al2 Sm phase with high thermal stability. Rod Mg3Bi2 phase precipitates when Bi is added, while the added metal Zn dissolves into δ-Mg matrix and δ-Mg17Al12 phase. The as-cast alloys exhibit the excellent tensile mechanical property. The tensile strength（δb） and elongation（δ） can reach 205-235 MPa and 8.5%-16.0% at ambient temperature, respectively. Meanwhile, they can also exceed 160 MPa and 14.0% at 423 K, respectively. The die-cast microstructures are refined obviously, and meanwhile the broken second phases distribute dispersedly. The die-cast alloys exhibit better tensile mechanical properties with the values of δb and δ of 240-285 MPa and 8.5%-16.5% at ambient temperature, respectively, and excellent flow property with the flow length of 1870-2420 mm. The die-cast tensile fractures at ambient temperature exhibit a typical character of ductile fracture.展开更多
Samarium（Sm） has been widely used in making aluminum（Al）-Sm magnet alloy materials. The research team for this study developed a molten salt electrolyte system which directly produces AI-Sm alloy to replace the en...Samarium（Sm） has been widely used in making aluminum（Al）-Sm magnet alloy materials. The research team for this study developed a molten salt electrolyte system which directly produces AI-Sm alloy to replace the energy intensive conventional distillation technology. In this study, molten melt density was measured and operation conditions were optimized to separate AI-Sm alloy product from the fluoride molten melt electrolysis media based on density differences, Archimedes＇ principle was applied to measure density for the basic molten fluoride system（BMFS： Na_3 AlF_6-AlF_3-LiF-MgF_2）electrolysis media in the temperature range from 905 to 1055 ℃.The impact of temperature（t） and the Al_2O_3 and Sm_2O_3 addition ratio（w_（（Al2O3））,w_（（Sm2O3）） in the basic fluoride system on molten melt density was examined. The fluoride molten melt density relationship was determined to be：ρ=3.11701-0.00802 w_（（Al2O3））＋0.027825 w_（（Sm2O3））-0.00117 t. The test results showed that molten density decreases with increase in temperature and Al_2O_3 addition ratio, and increases with the addition of Sm_2O_3, and/or Al_2O_3＋Sm_2O_3. The separation of Al-Sm（density 2.3 g/cm^3） product melt from the BMFS melt is achieved by controlling the BMFS density to less than 2.0 g/cm3. It is concluded that the optimal operation conditions to control the BMFS molten salt density to less than 2.0 g/cm^3 are：maintain addition of Al_2O_3＋Sm_2 O_3（w_（（Al2O3））＋w_（（Sm2O3））〈9% of Na_3AlF_6,Al_2O_3/Sm_2O_3 ratio（w_（（Al2O3））：w_（（Sm2O3）））〉 7：3, and temperature between 965 and 995 ℃.展开更多
The splat foils of Al-Sm alloys with 0.04-0.06mm in thickness were made by hammeranvil technique. The estimated cooling rute was 106K/ order of magnitude. The extended solid solubility of Sm in α-Al reached 0.5at. % ...The splat foils of Al-Sm alloys with 0.04-0.06mm in thickness were made by hammeranvil technique. The estimated cooling rute was 106K/ order of magnitude. The extended solid solubility of Sm in α-Al reached 0.5at. % Sm. The intermediate phase in the rapidlysolidified Al-Sm alloys is Al11Sm3 phase, which is stable only at temperatures above 1339K in equilibrium state and retained to ambient temperature as a metastable phase, whereas the equlibrium intermediate phase, Al3Sm, was restricted to occur.展开更多
Effect of the addition of Sm 2O 3 on CuO γ Al 2O 3 catalyst for CO oxidation reaction was investigated. The result shows that the right amount of Sm 2O 3 can promote the adsorption of the surface oxygen a...Effect of the addition of Sm 2O 3 on CuO γ Al 2O 3 catalyst for CO oxidation reaction was investigated. The result shows that the right amount of Sm 2O 3 can promote the adsorption of the surface oxygen and recovery of CuO γ Al 2O 3 catalyst. Sm 2O 3 plays an important role in change of γ Al 2O 3 phase into θ Al 2O 3 phase. In addition, the right amount of Sm 2O 3(5%) can improve the oxidation activity of the CuO γ Al 2O 3 catalyst. Whereas an excess of Sm 2O 3(10%) makes the CuO crystal in CuO γ Al 2O 3 catalyst become bigger and restrain the oxidation activity of the CuO γ Al 2O 3 catalyst.展开更多
基金Project(2013AA031001)supported by the National High-tech Research and Development Program of ChinaProject(2011A080403008)supported by the Major Science and Technology Project of Guangdong Province,China
文摘The microstructures and phase compositions of the as-cast and die-cast Mg-6.02Al-1.03 Sm, Mg-6.05Al-0.98Sm-0.56 Bi and Mg-5.95Al-1.01Sm-0.57 Zn alloys were investigated. Meanwhile, the tensile mechanical and flow properties were tested. The results show that the as-cast microstructure of Mg-6.02Al-1.03 Sm alloy is composed of δ-Mg matrix, discontinuous δ-Mg17Al12 phase and small block Al2 Sm phase with high thermal stability. Rod Mg3Bi2 phase precipitates when Bi is added, while the added metal Zn dissolves into δ-Mg matrix and δ-Mg17Al12 phase. The as-cast alloys exhibit the excellent tensile mechanical property. The tensile strength（δb） and elongation（δ） can reach 205-235 MPa and 8.5%-16.0% at ambient temperature, respectively. Meanwhile, they can also exceed 160 MPa and 14.0% at 423 K, respectively. The die-cast microstructures are refined obviously, and meanwhile the broken second phases distribute dispersedly. The die-cast alloys exhibit better tensile mechanical properties with the values of δb and δ of 240-285 MPa and 8.5%-16.5% at ambient temperature, respectively, and excellent flow property with the flow length of 1870-2420 mm. The die-cast tensile fractures at ambient temperature exhibit a typical character of ductile fracture.
基金Project supported by the National Natural Science Foundation of China(51564015,51674126)Graduate Student Innovation Special Fund of Jiangxi Province(YC2015-B064)+2 种基金Science and Technology Research Project of Jiangxi Department of Education(GJJ150664)Outstanding doctoral dissertation project fund of JXUST(YB2016007)Scientific Research Fund of JXUST(NSFJ2014-G09)
文摘Samarium（Sm） has been widely used in making aluminum（Al）-Sm magnet alloy materials. The research team for this study developed a molten salt electrolyte system which directly produces AI-Sm alloy to replace the energy intensive conventional distillation technology. In this study, molten melt density was measured and operation conditions were optimized to separate AI-Sm alloy product from the fluoride molten melt electrolysis media based on density differences, Archimedes＇ principle was applied to measure density for the basic molten fluoride system（BMFS： Na_3 AlF_6-AlF_3-LiF-MgF_2）electrolysis media in the temperature range from 905 to 1055 ℃.The impact of temperature（t） and the Al_2O_3 and Sm_2O_3 addition ratio（w_（（Al2O3））,w_（（Sm2O3）） in the basic fluoride system on molten melt density was examined. The fluoride molten melt density relationship was determined to be：ρ=3.11701-0.00802 w_（（Al2O3））＋0.027825 w_（（Sm2O3））-0.00117 t. The test results showed that molten density decreases with increase in temperature and Al_2O_3 addition ratio, and increases with the addition of Sm_2O_3, and/or Al_2O_3＋Sm_2O_3. The separation of Al-Sm（density 2.3 g/cm^3） product melt from the BMFS melt is achieved by controlling the BMFS density to less than 2.0 g/cm3. It is concluded that the optimal operation conditions to control the BMFS molten salt density to less than 2.0 g/cm^3 are：maintain addition of Al_2O_3＋Sm_2 O_3（w_（（Al2O3））＋w_（（Sm2O3））〈9% of Na_3AlF_6,Al_2O_3/Sm_2O_3 ratio（w_（（Al2O3））：w_（（Sm2O3）））〉 7：3, and temperature between 965 and 995 ℃.
文摘The splat foils of Al-Sm alloys with 0.04-0.06mm in thickness were made by hammeranvil technique. The estimated cooling rute was 106K/ order of magnitude. The extended solid solubility of Sm in α-Al reached 0.5at. % Sm. The intermediate phase in the rapidlysolidified Al-Sm alloys is Al11Sm3 phase, which is stable only at temperatures above 1339K in equilibrium state and retained to ambient temperature as a metastable phase, whereas the equlibrium intermediate phase, Al3Sm, was restricted to occur.
文摘Effect of the addition of Sm 2O 3 on CuO γ Al 2O 3 catalyst for CO oxidation reaction was investigated. The result shows that the right amount of Sm 2O 3 can promote the adsorption of the surface oxygen and recovery of CuO γ Al 2O 3 catalyst. Sm 2O 3 plays an important role in change of γ Al 2O 3 phase into θ Al 2O 3 phase. In addition, the right amount of Sm 2O 3(5%) can improve the oxidation activity of the CuO γ Al 2O 3 catalyst. Whereas an excess of Sm 2O 3(10%) makes the CuO crystal in CuO γ Al 2O 3 catalyst become bigger and restrain the oxidation activity of the CuO γ Al 2O 3 catalyst.
