Hypereutectic aluminum-silicon alloy powder of Al-20Si-0.35RE was synthesized by using the inert gas atomization technique. This powder was ball milled for different time and hot extruded subsequently. The microstruct...Hypereutectic aluminum-silicon alloy powder of Al-20Si-0.35RE was synthesized by using the inert gas atomization technique. This powder was ball milled for different time and hot extruded subsequently. The microstructure and electrical conductivity of alloy were studied by powder particle size analyzer, scanning electron microscope, X-ray diffraction and bridge resistance instrument respectively. It is indicated that the powder got by spray method have a better homogeneous distribution. The proper RE amount and milling time improved the conductivity due to either microstructural refining or decreasing of Si solid solubility in Al matrix. The conductivity changed with ball milling time, while unique high conductivity (75%IACS) could be achieved after milling for 12 h and hot-extruded 3 times. This kind of high conductivity aluminum-silicon alloy will be a potential conductor material which could be extensively used in the electrical engineering field.展开更多
Microstructures and mechanical properties of （Mg-2.0%Ce-0.7%Zn-0.7%Zr） alloy were studied. The results of scanning electron microscopy show that Mg12Ce phase mainly distributes at the grain boundaries. The fine (Mg1...Microstructures and mechanical properties of （Mg-2.0%Ce-0.7%Zn-0.7%Zr） alloy were studied. The results of scanning electron microscopy show that Mg12Ce phase mainly distributes at the grain boundaries. The fine (Mg12Ce) phase can apparently elevate recrystallization temperature by preventing the grain boundary migration. No dynamic recrystallization occurs during the hot-extrusion. The mechanical properties of as extruded specimens are （σb=278.5 MPa,） δ=12.0%, while those of the specimens annealed at 250 ℃ for 100 h are σb=（272.6 MPa,） δ=（11.3%,） which indicate that the alloy has good mechanical properties at room temperature.展开更多
Plastic deformation of sprayed alloy is an effective method to fabricate the hypereutectic aluminum-silicon alloy which combines good conductivity and toughness. In this study, Al-20Si-0.35 RE (wt%) alloy was synthesi...Plastic deformation of sprayed alloy is an effective method to fabricate the hypereutectic aluminum-silicon alloy which combines good conductivity and toughness. In this study, Al-20Si-0.35 RE (wt%) alloy was synthesized by spray atomization and deposition technique. The sprayed deposition and over-spray powder were hot-extruded and plastic deformed respectively. Microstructure and conductivity were systematically performed in order to understand the influence of deformation on microstructure and conductivity of the hypereutectic alloy. The Si particles are refining and uniformly distributed in the Al matrix due to the proper addition of rare earth metal and the rapid solidification preparation method. The microstructure of plastic deformed alloy has invariably indicated that severe plastic deformation lead to the even refinement of microstructure. Both the conductivity of over-spray powder extrusion and sprayed deposition extrusion were obviously improved after plastic deformation. Possible mechanisms of deformation on microstructure and conductivity of hypereutectic aluminum-silicon alloy are discussed.展开更多
基金Shanghai Science and Technology Expertise Program (10QB1400800)Shanghai Science and Technology Committee Foundation (08DZ2201300)National Natural Science Foundation of China (50901052)
文摘Hypereutectic aluminum-silicon alloy powder of Al-20Si-0.35RE was synthesized by using the inert gas atomization technique. This powder was ball milled for different time and hot extruded subsequently. The microstructure and electrical conductivity of alloy were studied by powder particle size analyzer, scanning electron microscope, X-ray diffraction and bridge resistance instrument respectively. It is indicated that the powder got by spray method have a better homogeneous distribution. The proper RE amount and milling time improved the conductivity due to either microstructural refining or decreasing of Si solid solubility in Al matrix. The conductivity changed with ball milling time, while unique high conductivity (75%IACS) could be achieved after milling for 12 h and hot-extruded 3 times. This kind of high conductivity aluminum-silicon alloy will be a potential conductor material which could be extensively used in the electrical engineering field.
文摘Microstructures and mechanical properties of （Mg-2.0%Ce-0.7%Zn-0.7%Zr） alloy were studied. The results of scanning electron microscopy show that Mg12Ce phase mainly distributes at the grain boundaries. The fine (Mg12Ce) phase can apparently elevate recrystallization temperature by preventing the grain boundary migration. No dynamic recrystallization occurs during the hot-extrusion. The mechanical properties of as extruded specimens are （σb=278.5 MPa,） δ=12.0%, while those of the specimens annealed at 250 ℃ for 100 h are σb=（272.6 MPa,） δ=（11.3%,） which indicate that the alloy has good mechanical properties at room temperature.
基金Foundation item: Shanghai Science and Technology Expertise Program (10QB1400800)Shanghai Science and Technology Committee Foundation (08DZ2201300)National Natural Science Foundation of China (50901052)
文摘Plastic deformation of sprayed alloy is an effective method to fabricate the hypereutectic aluminum-silicon alloy which combines good conductivity and toughness. In this study, Al-20Si-0.35 RE (wt%) alloy was synthesized by spray atomization and deposition technique. The sprayed deposition and over-spray powder were hot-extruded and plastic deformed respectively. Microstructure and conductivity were systematically performed in order to understand the influence of deformation on microstructure and conductivity of the hypereutectic alloy. The Si particles are refining and uniformly distributed in the Al matrix due to the proper addition of rare earth metal and the rapid solidification preparation method. The microstructure of plastic deformed alloy has invariably indicated that severe plastic deformation lead to the even refinement of microstructure. Both the conductivity of over-spray powder extrusion and sprayed deposition extrusion were obviously improved after plastic deformation. Possible mechanisms of deformation on microstructure and conductivity of hypereutectic aluminum-silicon alloy are discussed.
