A Cu-10wt%Fe composite was prepared through hot-pressed sintering,and the material was subsequently solution treated.The hot-pressed sintered and solution treated materials were rolled and aged.The precipitation behav...A Cu-10wt%Fe composite was prepared through hot-pressed sintering,and the material was subsequently solution treated.The hot-pressed sintered and solution treated materials were rolled and aged.The precipitation behavior and performance changes were systematically studied by using scanning electron microscopy and transmission electron microscopy.In contrast to the hot-pressed sintered specimen,the solution treatment significantly affects the thermal stability and properties of the Cu-10wt%Fe composite.The Cu-10wt%Fe composite was prepared after solid solution,cold rolling and aging at 773 K for 1 h,and it obtained excellent tensile strength of 494 MPa,uniform elongation of 16.3%,electrical conductivity of 51.1%IACS and softening temperature of 838 K.Mechanisms for the distinct difference in thermal stability and properties between hot-pressed sintered and solution treated specimens were analyzed.These findings provide a theoretical basis for designing high-performance Cu-based in-situ composites by post treatment.展开更多
The effects of intermediate annealings on the microstructure, the strength and the electrical resistivity of deformation-processed Cu-Fe in-situ composites were studied. The results show that intermediate annealings f...The effects of intermediate annealings on the microstructure, the strength and the electrical resistivity of deformation-processed Cu-Fe in-situ composites were studied. The results show that intermediate annealings favour the formation of uniform tiny fibres from the iron dendrites but they have no obvious effect on the strength of the composite. The bigger the strain is, the higher the strength is. As the strain increases, the resistivity increases due to the increase of interface density. Intermediate annealings result in notable decreasing resistivity due to the precipitation of the iron atoms from the Cu matrix and decrease of solute scattering resistivity. The doping with Zr improves the strength of the composite slightly and the ultimate tensile strength(UTS) increases about 10%. The colligated performances of deformation-processed Cu-11.5%Fe and Cu- 11.5%Fe-Zr composites at strain η= 5.37 are 64.6% IACS/752MPa and 61.4% IACS/824MPa respectively.展开更多
Cu-Fe composite oxides were prepared by co-precipitation method and tested for higher alcohol synthesis from syngas. The selectivity to C2＋OH and C6＋OH in alcohol distribution was very high while the methane product...Cu-Fe composite oxides were prepared by co-precipitation method and tested for higher alcohol synthesis from syngas. The selectivity to C2＋OH and C6＋OH in alcohol distribution was very high while the methane product fraction in hydrocarbon distribution was rather low, demonstrating a promising potential in higher alcohols synthesis from syngas. The distribution of alcohols and hydrocarbons approximately obeyed Anderson-Schulz-Flory distribution with similar chain growth probability, indicating alcohols and hydrocarbons derived from the same intermediates. The effects of Cu/Fe molar ratio, reaction temperature and gas hourly space velocity （GHSV） on catalytic performance were studied in detail. The sample with a Cu/Fe molar ratio of 10/1 exhibited the best catalytic performance. Higher reaction temperature accelerated water-gas-shift reaction and led to lower total alcohols selectivity. GHSV showed great effect on catalytic performance and higher GHSV increased the total alcohol selectivity, indicating there existed visible dehydration reaction of alcohol into hydrocarbon.展开更多
采用酸性和碱性铜盐废液中和,有机酸作为添加剂,用还原铁粉置换含铜废液中铜,制备了含铜量为20%的铜包覆铁的复合粉。采用火焰原子吸收光谱法、惰气脉冲红外热导法、扫描电子显微镜和X射线衍射对粉末的成分、形貌进行了研究,分析了铜离...采用酸性和碱性铜盐废液中和,有机酸作为添加剂,用还原铁粉置换含铜废液中铜,制备了含铜量为20%的铜包覆铁的复合粉。采用火焰原子吸收光谱法、惰气脉冲红外热导法、扫描电子显微镜和X射线衍射对粉末的成分、形貌进行了研究,分析了铜离子浓度、反应时间、干燥还原条件对复合粉特性的影响;并对粉末进行了真空热压试验。实验结果表明：铜铁复合粉为包覆型结构,Cu层厚度约为1μm;溶液中铜离子浓度愈高,反应速率愈快,反应时间在25~30 m in范围内;较合适的干燥还原条件应为：温度在500~650℃之间,时间2~3h。粉末由Cu和Fe两相构成,没有其他杂质相。≤74μm较≤150μm的粉末的烧结试样的HRB硬度和抗弯强度在相应的温度下高,真空热压性能比较稳定的温度区间是700~750℃。展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant No.52101181).
文摘A Cu-10wt%Fe composite was prepared through hot-pressed sintering,and the material was subsequently solution treated.The hot-pressed sintered and solution treated materials were rolled and aged.The precipitation behavior and performance changes were systematically studied by using scanning electron microscopy and transmission electron microscopy.In contrast to the hot-pressed sintered specimen,the solution treatment significantly affects the thermal stability and properties of the Cu-10wt%Fe composite.The Cu-10wt%Fe composite was prepared after solid solution,cold rolling and aging at 773 K for 1 h,and it obtained excellent tensile strength of 494 MPa,uniform elongation of 16.3%,electrical conductivity of 51.1%IACS and softening temperature of 838 K.Mechanisms for the distinct difference in thermal stability and properties between hot-pressed sintered and solution treated specimens were analyzed.These findings provide a theoretical basis for designing high-performance Cu-based in-situ composites by post treatment.
文摘The effects of intermediate annealings on the microstructure, the strength and the electrical resistivity of deformation-processed Cu-Fe in-situ composites were studied. The results show that intermediate annealings favour the formation of uniform tiny fibres from the iron dendrites but they have no obvious effect on the strength of the composite. The bigger the strain is, the higher the strength is. As the strain increases, the resistivity increases due to the increase of interface density. Intermediate annealings result in notable decreasing resistivity due to the precipitation of the iron atoms from the Cu matrix and decrease of solute scattering resistivity. The doping with Zr improves the strength of the composite slightly and the ultimate tensile strength(UTS) increases about 10%. The colligated performances of deformation-processed Cu-11.5%Fe and Cu- 11.5%Fe-Zr composites at strain η= 5.37 are 64.6% IACS/752MPa and 61.4% IACS/824MPa respectively.
基金the State Key Fundamental Research Program(Ministry of Science and Technology of China,No.2011CBA00501)Shanghai Municipal Science and Technology Commission,China(Grant No:11DZ1200300)the Foundation of State Key Laboratory of Coal Conversion(Grant No:1112610)
文摘Cu-Fe composite oxides were prepared by co-precipitation method and tested for higher alcohol synthesis from syngas. The selectivity to C2＋OH and C6＋OH in alcohol distribution was very high while the methane product fraction in hydrocarbon distribution was rather low, demonstrating a promising potential in higher alcohols synthesis from syngas. The distribution of alcohols and hydrocarbons approximately obeyed Anderson-Schulz-Flory distribution with similar chain growth probability, indicating alcohols and hydrocarbons derived from the same intermediates. The effects of Cu/Fe molar ratio, reaction temperature and gas hourly space velocity （GHSV） on catalytic performance were studied in detail. The sample with a Cu/Fe molar ratio of 10/1 exhibited the best catalytic performance. Higher reaction temperature accelerated water-gas-shift reaction and led to lower total alcohols selectivity. GHSV showed great effect on catalytic performance and higher GHSV increased the total alcohol selectivity, indicating there existed visible dehydration reaction of alcohol into hydrocarbon.
文摘采用酸性和碱性铜盐废液中和,有机酸作为添加剂,用还原铁粉置换含铜废液中铜,制备了含铜量为20%的铜包覆铁的复合粉。采用火焰原子吸收光谱法、惰气脉冲红外热导法、扫描电子显微镜和X射线衍射对粉末的成分、形貌进行了研究,分析了铜离子浓度、反应时间、干燥还原条件对复合粉特性的影响;并对粉末进行了真空热压试验。实验结果表明：铜铁复合粉为包覆型结构,Cu层厚度约为1μm;溶液中铜离子浓度愈高,反应速率愈快,反应时间在25~30 m in范围内;较合适的干燥还原条件应为：温度在500~650℃之间,时间2~3h。粉末由Cu和Fe两相构成,没有其他杂质相。≤74μm较≤150μm的粉末的烧结试样的HRB硬度和抗弯强度在相应的温度下高,真空热压性能比较稳定的温度区间是700~750℃。
