The electrical resistivity and viscosity of liquid hypoeutectic Al 7%Si and hypereutectic Al 18%Si alloys, and the influences of trace strontium and phosphorus on them were investigated. The trace additions of the t...The electrical resistivity and viscosity of liquid hypoeutectic Al 7%Si and hypereutectic Al 18%Si alloys, and the influences of trace strontium and phosphorus on them were investigated. The trace additions of the two elements increase the electrical resistivity. At the precipitation temperatures of primary phase, the electrical resistivity exhibits a discontinuity for all experimental Al Si alloys. In the discontinuity the electrical resistivity, respectively, decreases and increases abruptly for Al 7%Si alloys and Al 18%Si alloys. Phosphorus and strontium both have some effects on the discontinuity temperature and the jump value of electrical resistivity of Al 18%Si alloys, but strontium hardly has effect on them in Al 7%Si alloys. The trace additions of strontium and phosphorus increase the viscosity of the experimental alloy.展开更多
In-situ observation of eutectic solidification of Cr12MoV steel was conducted using high temperature confocal laser-scanning microscopy. The semi-solid isothermal treatment temperature of the steel was determined by t...In-situ observation of eutectic solidification of Cr12MoV steel was conducted using high temperature confocal laser-scanning microscopy. The semi-solid isothermal treatment temperature of the steel was determined by thermodynamic calculation using Thermo-cal software. At the same time, the infl uences of isothermal treatment temperature and time on eutectic carbides in the steel were also studied. The results show that when the liquid metal cools at the rate of 47 °C·min-1, the eutectic reaction occurs rapidly at 1,214.7 °C in one second with the reticular liquid around austenite dendrites, transforming into a network of eutectic structure. After being held at 1,300 °C for 30 min, the carbide network is broken due to the impingement of refi ned primary austenite dendrites and secondary dendrites arms, and the thickness of eutectic structure is reduced.展开更多
Molecular dynamics simulations of computer have been performed on the local structure and bond orientation order of liquid metal Pb at 623 K,Results show that,at point near melting temperature,the local structures of ...Molecular dynamics simulations of computer have been performed on the local structure and bond orientation order of liquid metal Pb at 623 K,Results show that,at point near melting temperature,the local structures of liquid metal Pb show cubic symmetry,and the long-range correlation of this symmetry is weak.展开更多
Besed on the embedded atom method,molecular dynamics simulations have been performed on microdynamics behavior of liquid transition metal.Cu and Ni.Mean-square displacement,self-diffusion coefficient and velocity self...Besed on the embedded atom method,molecular dynamics simulations have been performed on microdynamics behavior of liquid transition metal.Cu and Ni.Mean-square displacement,self-diffusion coefficient and velocity self-correlation function have been calculated.In addition,effects of many body interactions have been discussed.展开更多
1 Introduction Scattered waves is a broader category of seismic waves, as the seismic wave change caused by geological heterogeneity in 3D space can be classified into seismic scattering （Wu and Aki, 1993）.
文摘The electrical resistivity and viscosity of liquid hypoeutectic Al 7%Si and hypereutectic Al 18%Si alloys, and the influences of trace strontium and phosphorus on them were investigated. The trace additions of the two elements increase the electrical resistivity. At the precipitation temperatures of primary phase, the electrical resistivity exhibits a discontinuity for all experimental Al Si alloys. In the discontinuity the electrical resistivity, respectively, decreases and increases abruptly for Al 7%Si alloys and Al 18%Si alloys. Phosphorus and strontium both have some effects on the discontinuity temperature and the jump value of electrical resistivity of Al 18%Si alloys, but strontium hardly has effect on them in Al 7%Si alloys. The trace additions of strontium and phosphorus increase the viscosity of the experimental alloy.
基金financially supported by the National Natural Science Foundation of China(No.51204092)the Open Project of Shanghai Key Laboratory of Modern Metallurgy and Materials Processing(No.SELF-2012-02)
文摘In-situ observation of eutectic solidification of Cr12MoV steel was conducted using high temperature confocal laser-scanning microscopy. The semi-solid isothermal treatment temperature of the steel was determined by thermodynamic calculation using Thermo-cal software. At the same time, the infl uences of isothermal treatment temperature and time on eutectic carbides in the steel were also studied. The results show that when the liquid metal cools at the rate of 47 °C·min-1, the eutectic reaction occurs rapidly at 1,214.7 °C in one second with the reticular liquid around austenite dendrites, transforming into a network of eutectic structure. After being held at 1,300 °C for 30 min, the carbide network is broken due to the impingement of refi ned primary austenite dendrites and secondary dendrites arms, and the thickness of eutectic structure is reduced.
基金Supported by the Laboratory of Rapidly Solidified Non-equilibrium Alloys,Institute of Metal Research,Academia Sinica.
文摘Molecular dynamics simulations of computer have been performed on the local structure and bond orientation order of liquid metal Pb at 623 K,Results show that,at point near melting temperature,the local structures of liquid metal Pb show cubic symmetry,and the long-range correlation of this symmetry is weak.
基金Supported by the Laboratory of Rapidly Solidified Non-equilibrium Alloys,Institute of Metal Research,Academia Sinica.
文摘Besed on the embedded atom method,molecular dynamics simulations have been performed on microdynamics behavior of liquid transition metal.Cu and Ni.Mean-square displacement,self-diffusion coefficient and velocity self-correlation function have been calculated.In addition,effects of many body interactions have been discussed.
基金supported by the Petro China Innovation Foundation(#2014D-5006-0303)National Natural Science Foundation of China(NSF,#41204091)Key Laboratory Research Project of Shaan’xi Provincial Department of Education(#13JS093)
文摘1 Introduction Scattered waves is a broader category of seismic waves, as the seismic wave change caused by geological heterogeneity in 3D space can be classified into seismic scattering （Wu and Aki, 1993）.
