The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform

Bingqing Wei - One of the best experts on this subject based on the ideXlab platform.

  • determining thermophysical properties of normal and Metastable Liquid zr fe alloys by electrostatic levitation method
    Metallurgical and Materials Transactions A-physical Metallurgy and Materials Science, 2020
    Co-Authors: Chen Zheng, H P Wang, P F Zou, Bingqing Wei
    Abstract:

    The thermophysical properties of Liquid Zr-Fe alloys were experimentally measured by an electrostatic levitation technique. A series of undercoolings from 45 K to 410 K were achieved for these Liquid alloys in the natural radiation cooling process. Since the experiments were conducted in high-vacuum and containerless conditions, the ratio of the specific heat to the hemispherical emissivity was deduced and showed a quadratic relationship with temperature. For the eutectic Zr76Fe24 alloy, the hypercooling of 306 K and hemispherical emissivity were derived theoretically due to its low Liquidus temperature and scarce volatilization. Through digital image processing, the alloy densities were measured, and the results depended linearly on temperature over a wide temperature range covering both superheated and undercooled Liquid states. The absolute value of the temperature coefficient tended to increase with increasing Fe contents, indicating that the Liquid density sensitivity increased with increasing Fe contents. The surface tension and viscosity were also determined by a drop oscillation method under the electrostatic levitation condition.

  • density measurement and atomic structure simulation of Metastable Liquid ti ni alloys
    Metallurgical and Materials Transactions A-physical Metallurgy and Materials Science, 2018
    Co-Authors: P F Zou, H P Wang, S J Yang, Bingqing Wei
    Abstract:

    The temperature dependence of the densities of Liquid Ti-Ni alloys was investigated by the electrostatic levitation technique and molecular dynamics simulation. The average cooling rate by natural radiation decreases with a reduction in Ti content and reaches its minimum at Ti55Ni45 alloy. The Ti-Ni alloy system exhibits a negative excess volume and it becomes smaller with the increase in undercooling. This indicates that the interactions among atoms are enhanced with the decrease in temperature. The pair correlation functions and static structure factors are obtained from the molecular dynamics results. It is found that the packing of the Ni atoms does not occur through replacement of the Ti atoms with the addition of Ni atoms. In addition, the clusters are abundant in Liquid Ti-Ni alloys, and a tetragonal bipyramid atomic configuration of may exist. It is found that the Ni-Ni bonds transform to Ti-Ni bonds with the increase in Ni content.

  • density determination and simulation of inconel 718 alloy at normal and Metastable Liquid states
    Journal of Materials Science & Technology, 2017
    Co-Authors: H P Wang, P F Zou, S J Yang, C H Zheng, Bingqing Wei
    Abstract:

    Abstract The density of Liquid Inconel 718 alloy was experimentally measured by electrostatic levitation technique, where the maximum undercooling of 100 K was realized for the commercial sample. The measured density of Liquid Inconel 718 alloy is 7.39 g cm−3 at the Liquidus temperature of 1663 K which was confirmed by DSC experiment, with the linear temperature coefficient of −6.89 × 10−4 g cm−3 K−1. Correspondingly, four ternary Ni-Cr-Fe compositions were designed to simulate the density of Liquid Inconel 718 alloy with 16000 atoms, from which the Liquid structure is revealed by pair distribution function. The predicted result shows a remarkable enhancement with the decrease of temperature at the first neighbor distance.

  • molecular dynamics prediction and experimental evidence for density of normal and Metastable Liquid zirconium
    Chemical Physics Letters, 2016
    Co-Authors: H P Wang, S J Yang, Bingqing Wei
    Abstract:

    Abstract The density of normal and Metastable undercooled Liquid zirconium was predicted by performing molecular dynamics calculation with a system consisting of 4000 atoms and measured by electrostatic levitation experiments. The results show that the density increases linearly with the descending of temperature, including a maximum undercooling of 928 K. The density is 6.00 g cm −3 at the melting temperature, which agrees well with the experimental result of 6.06 g cm −3 . Furthermore, the atomic number is increased to 32,000 on the basis of 4000 atoms and there appears only 0.02% difference. Besides, the pair distribution function was applied to display the atomic structure, which indicates the Liquid structure change occurs at the first neighbor distance.

  • surface tension measurement of Metastable Liquid ti al nb alloys
    Applied Physics A, 2011
    Co-Authors: Kaiming Zhou, H P Wang, J Chang, Bingqing Wei
    Abstract:

    Thermophysical properties of Liquid alloys are usually difficult to measure, especially for high melting point and reactive alloys. In this work, the surface tensions of superheated and undercooled Liquid Ti55Al45, Ti50Al45Nb5 and Ti45Al45Nb10 alloys are determined by using oscillating drop method under electromagnetic levitation state. The experimental results of Ti–Al and Ti–Al–Nb alloys display linear temperature dependence. The maximum undercoolings of 259 (0.143TL), 268 (0.146TL) and 275 K (0.147TL) are respectively achieved for these three alloys. Furthermore, the viscosities of Liquid Ti55−xAl45Nbx alloys are also derived from the experimental results.

H P Wang - One of the best experts on this subject based on the ideXlab platform.

  • determining thermophysical properties of normal and Metastable Liquid zr fe alloys by electrostatic levitation method
    Metallurgical and Materials Transactions A-physical Metallurgy and Materials Science, 2020
    Co-Authors: Chen Zheng, H P Wang, P F Zou, Bingqing Wei
    Abstract:

    The thermophysical properties of Liquid Zr-Fe alloys were experimentally measured by an electrostatic levitation technique. A series of undercoolings from 45 K to 410 K were achieved for these Liquid alloys in the natural radiation cooling process. Since the experiments were conducted in high-vacuum and containerless conditions, the ratio of the specific heat to the hemispherical emissivity was deduced and showed a quadratic relationship with temperature. For the eutectic Zr76Fe24 alloy, the hypercooling of 306 K and hemispherical emissivity were derived theoretically due to its low Liquidus temperature and scarce volatilization. Through digital image processing, the alloy densities were measured, and the results depended linearly on temperature over a wide temperature range covering both superheated and undercooled Liquid states. The absolute value of the temperature coefficient tended to increase with increasing Fe contents, indicating that the Liquid density sensitivity increased with increasing Fe contents. The surface tension and viscosity were also determined by a drop oscillation method under the electrostatic levitation condition.

  • density measurement and atomic structure simulation of Metastable Liquid ti ni alloys
    Metallurgical and Materials Transactions A-physical Metallurgy and Materials Science, 2018
    Co-Authors: P F Zou, H P Wang, S J Yang, Bingqing Wei
    Abstract:

    The temperature dependence of the densities of Liquid Ti-Ni alloys was investigated by the electrostatic levitation technique and molecular dynamics simulation. The average cooling rate by natural radiation decreases with a reduction in Ti content and reaches its minimum at Ti55Ni45 alloy. The Ti-Ni alloy system exhibits a negative excess volume and it becomes smaller with the increase in undercooling. This indicates that the interactions among atoms are enhanced with the decrease in temperature. The pair correlation functions and static structure factors are obtained from the molecular dynamics results. It is found that the packing of the Ni atoms does not occur through replacement of the Ti atoms with the addition of Ni atoms. In addition, the clusters are abundant in Liquid Ti-Ni alloys, and a tetragonal bipyramid atomic configuration of may exist. It is found that the Ni-Ni bonds transform to Ti-Ni bonds with the increase in Ni content.

  • density determination and simulation of inconel 718 alloy at normal and Metastable Liquid states
    Journal of Materials Science & Technology, 2017
    Co-Authors: H P Wang, P F Zou, S J Yang, C H Zheng, Bingqing Wei
    Abstract:

    Abstract The density of Liquid Inconel 718 alloy was experimentally measured by electrostatic levitation technique, where the maximum undercooling of 100 K was realized for the commercial sample. The measured density of Liquid Inconel 718 alloy is 7.39 g cm−3 at the Liquidus temperature of 1663 K which was confirmed by DSC experiment, with the linear temperature coefficient of −6.89 × 10−4 g cm−3 K−1. Correspondingly, four ternary Ni-Cr-Fe compositions were designed to simulate the density of Liquid Inconel 718 alloy with 16000 atoms, from which the Liquid structure is revealed by pair distribution function. The predicted result shows a remarkable enhancement with the decrease of temperature at the first neighbor distance.

  • molecular dynamics prediction and experimental evidence for density of normal and Metastable Liquid zirconium
    Chemical Physics Letters, 2016
    Co-Authors: H P Wang, S J Yang, Bingqing Wei
    Abstract:

    Abstract The density of normal and Metastable undercooled Liquid zirconium was predicted by performing molecular dynamics calculation with a system consisting of 4000 atoms and measured by electrostatic levitation experiments. The results show that the density increases linearly with the descending of temperature, including a maximum undercooling of 928 K. The density is 6.00 g cm −3 at the melting temperature, which agrees well with the experimental result of 6.06 g cm −3 . Furthermore, the atomic number is increased to 32,000 on the basis of 4000 atoms and there appears only 0.02% difference. Besides, the pair distribution function was applied to display the atomic structure, which indicates the Liquid structure change occurs at the first neighbor distance.

  • surface tension measurement of Metastable Liquid ti al nb alloys
    Applied Physics A, 2011
    Co-Authors: Kaiming Zhou, H P Wang, J Chang, Bingqing Wei
    Abstract:

    Thermophysical properties of Liquid alloys are usually difficult to measure, especially for high melting point and reactive alloys. In this work, the surface tensions of superheated and undercooled Liquid Ti55Al45, Ti50Al45Nb5 and Ti45Al45Nb10 alloys are determined by using oscillating drop method under electromagnetic levitation state. The experimental results of Ti–Al and Ti–Al–Nb alloys display linear temperature dependence. The maximum undercoolings of 259 (0.143TL), 268 (0.146TL) and 275 K (0.147TL) are respectively achieved for these three alloys. Furthermore, the viscosities of Liquid Ti55−xAl45Nbx alloys are also derived from the experimental results.

Yu O Liashenko - One of the best experts on this subject based on the ideXlab platform.

  • differences in the interfacial reaction between cu substrate and Metastable supercooled Liquid sn cu solder or solid sn cu solder at 222 c experimental results versus theoretical model calculations
    Acta Materialia, 2015
    Co-Authors: Yu O Liashenko, F Hodaj
    Abstract:

    Abstract Interfacial reactions between a Cu substrate and a Metastable supercooled Liquid Sn–Cu solder at 222 °C are studied for the first time. The principal aim of this study is to compare the differences between Cu/solid Sn and Cu/Metastable Liquid Sn interfacial reactions at a rigorously identical temperature and to determine the role of Liquid state in the kinetics of interfacial reactions as well as in the morphology of the reaction product. For this purpose, we have performed specific experiments for the interfacial reaction between Metastable Liquid Sn–0.7 wt%Cu alloy and Cu substrate at a temperature of 222 °C, that is 5 K lower than the melting point of this alloy (227 °C), and for reaction times as long as 32 h. These experiments have been carried out using a Differential Scanning Calorimetry apparatus in order to monitor and control the physical state of the alloy as well as to set the accurate reaction temperature. Similar experiments were performed to study the reaction kinetics between the Cu substrate and solid Sn–0.7 wt%Cu alloy at the same temperature. A large difference in the growth kinetics and the morphology of the η-Cu6Sn5 phase was observed when a change in the physical state of the alloy occurs at identical temperature. Using thermodynamic and kinetic models of growth kinetics of the reaction layer at reactive interfaces, the driving force of η-Cu6Sn5 formation cannot be the cause of this large difference. A theoretical analysis of the growth kinetics of the η-Cu6Sn5 phase and comparison of its growth in both configurations are compared.

F Hodaj - One of the best experts on this subject based on the ideXlab platform.

  • differences in the interfacial reaction between cu substrate and Metastable supercooled Liquid sn cu solder or solid sn cu solder at 222 c experimental results versus theoretical model calculations
    Acta Materialia, 2015
    Co-Authors: Yu O Liashenko, F Hodaj
    Abstract:

    Abstract Interfacial reactions between a Cu substrate and a Metastable supercooled Liquid Sn–Cu solder at 222 °C are studied for the first time. The principal aim of this study is to compare the differences between Cu/solid Sn and Cu/Metastable Liquid Sn interfacial reactions at a rigorously identical temperature and to determine the role of Liquid state in the kinetics of interfacial reactions as well as in the morphology of the reaction product. For this purpose, we have performed specific experiments for the interfacial reaction between Metastable Liquid Sn–0.7 wt%Cu alloy and Cu substrate at a temperature of 222 °C, that is 5 K lower than the melting point of this alloy (227 °C), and for reaction times as long as 32 h. These experiments have been carried out using a Differential Scanning Calorimetry apparatus in order to monitor and control the physical state of the alloy as well as to set the accurate reaction temperature. Similar experiments were performed to study the reaction kinetics between the Cu substrate and solid Sn–0.7 wt%Cu alloy at the same temperature. A large difference in the growth kinetics and the morphology of the η-Cu6Sn5 phase was observed when a change in the physical state of the alloy occurs at identical temperature. Using thermodynamic and kinetic models of growth kinetics of the reaction layer at reactive interfaces, the driving force of η-Cu6Sn5 formation cannot be the cause of this large difference. A theoretical analysis of the growth kinetics of the η-Cu6Sn5 phase and comparison of its growth in both configurations are compared.

Hye Jung Chang - One of the best experts on this subject based on the ideXlab platform.

  • in situ formation of two glassy phases in the nd zr al co alloy system
    Scripta Materialia, 2007
    Co-Authors: E S Park, E Y Jeong, A R Kwon, A Gebert, L Schultz, Hye Jung Chang
    Abstract:

    The Nd–Zr–Al–Co alloy system undergoes Metastable Liquid phase separation over a wide composition range during quenching and subsequently solidifies into two different Nd-rich and Zr-rich amorphous phases. As-quenched samples consist of two amorphous phases of spherical shape with a wide range of length scale (from several nm to μm), and exhibit two distinct exothermic reactions during continuous heating. Viscosity and magnetic properties have been measured to identify potential practical applications of phase-separating metallic glasses.

  • in situ formation of two amorphous phases by Liquid phase separation in y ti al co alloy
    Applied Physics Letters, 2004
    Co-Authors: Byoungjun Park, Hye Jung Chang
    Abstract:

    The Y28Ti28Al24Co20 alloy undergoes Metastable Liquid phase separation in the under-cooled Liquid state and subsequently solidifies into two different Y-rich and Ti-rich amorphous phases. Secondary phase separation occurs due to the supersaturation of the primary separated Liquids as the temperature decreases. Depending on the degree of local undercooling, a wide range of length scale of the microstructure is observed. The characteristic length scale of the two amorphous phases is ∼250nm near the air side of the ribbon, and ∼25nm near the wheel side of the ribbon.