The ratio,of the temperature gradient at the solidifiationfront to the solidification rate of solid-liquid interface,plays a large part in columnar grain growth.The transient temperature fields of directional solidifi...The ratio,of the temperature gradient at the solidifiationfront to the solidification rate of solid-liquid interface,plays a large part in columnar grain growth.The transient temperature fields of directional solidification of Al-Ni-Co alloy were studied by employing a finite element method.The temperature gradient at the solidification front and the solidification rate were analyzed for molten steels pouring at different temperatures.The results show that with different initial pouring temperatures,the individual ratio of the temperature gradient at solidification front to the solidification rate soars up in the initial stage of solidification,then varies within 2,000-6,000℃.s.cm-2,and finally goes down rapidly and even tend to be closed to each other when the solidification thickness reaches 5-6 cm.The simulation result is consistent with the practical production which can provide an available reference for process optimization of directional solidified Al-Ni-Co alloy.展开更多
CoAl LDHs with different molar ratio of Ni have been prepared by chemical co -precipitation method.XRD results show that these materials have layered struc tures.Electrochemical tests show that Co(Ni)Al LDHs as electr...CoAl LDHs with different molar ratio of Ni have been prepared by chemical co -precipitation method.XRD results show that these materials have layered struc tures.Electrochemical tests show that Co(Ni)Al LDHs as electrode material hav e typical capacit ive properties in a wide voltage range of0.0to0.6V;Co(Ni)Al LDH(Ni∶Co =4∶6)as an electrode material has the highest capacitance of960F · g -1 and good cycling performance.But the poor capacitive properties of NiAl LDH electrode are showed in a narrow voltage range of0.3to0.55V.展开更多
文摘The ratio,of the temperature gradient at the solidifiationfront to the solidification rate of solid-liquid interface,plays a large part in columnar grain growth.The transient temperature fields of directional solidification of Al-Ni-Co alloy were studied by employing a finite element method.The temperature gradient at the solidification front and the solidification rate were analyzed for molten steels pouring at different temperatures.The results show that with different initial pouring temperatures,the individual ratio of the temperature gradient at solidification front to the solidification rate soars up in the initial stage of solidification,then varies within 2,000-6,000℃.s.cm-2,and finally goes down rapidly and even tend to be closed to each other when the solidification thickness reaches 5-6 cm.The simulation result is consistent with the practical production which can provide an available reference for process optimization of directional solidified Al-Ni-Co alloy.
文摘CoAl LDHs with different molar ratio of Ni have been prepared by chemical co -precipitation method.XRD results show that these materials have layered struc tures.Electrochemical tests show that Co(Ni)Al LDHs as electrode material hav e typical capacit ive properties in a wide voltage range of0.0to0.6V;Co(Ni)Al LDH(Ni∶Co =4∶6)as an electrode material has the highest capacitance of960F · g -1 and good cycling performance.But the poor capacitive properties of NiAl LDH electrode are showed in a narrow voltage range of0.3to0.55V.
