In the framework of systematic science of alloys,the average molar property（volume and potential energy） functions of disordered alloys were established.From these functions,the average molar property functions,part...In the framework of systematic science of alloys,the average molar property（volume and potential energy） functions of disordered alloys were established.From these functions,the average molar property functions,partial molar property functions,derivative functions with respect to composition,general equation of relationship between partial and average molar properties of components,difference equation and constraining equation of different values between partial and average molar properties,as well as general Gibbs-Duhem formula were derived.It was proved that the partial molar properties calculated from various combinative functions of average molar properties of alloys are equal,but in general,the partial molar properties are not equal to the average molar properties of a given component.This means that the partial molar properties cannot represent the corresponding properties of the component.All the equations and functions established in this work were proved to be correct by calculating the results of partial and average atomic volumes of components as well as average atomic volumes of alloys in the Au-Ni system.展开更多
Bimetallic nanomaterials are of great signifi- cance to both fundamental research and industrial appli- cations. Their physicochemical performances are critically dependent on their architectures and electronic struct...Bimetallic nanomaterials are of great signifi- cance to both fundamental research and industrial appli- cations. Their physicochemical performances are critically dependent on their architectures and electronic structures. Here, it was reported a controlled synthesis of Au/Ni bimetallic nanocrystals with different nanostructures, i.e., dumbbell, core@shell and alloyed nanostructures in a one- pot synthesis procedure. Detailed structural characteriza- tions were conducted with the combination of transmission electron microscopy （TEM） and X-ray diffraction （XRD）. Even there is a large lattice mismatch between Au and Ni, Au@Ni core@shell nanocrystals are obtained with the seeded growth method. The growth mechanism was deeply investigated. Triphenylphosphine is demonstrated to be an effective capping agent to modify the interfacial energy to form core@shell nanocrystals, and the higher temperature is proved to be a key role in obtaining alloyed nanocrystals.展开更多
In a previous paper it was shown that the normal spectral emissivity at 684.5 nm of a binary alloy can be lower than that of the pure constituent components. For the actual probes it was found that the observed values...In a previous paper it was shown that the normal spectral emissivity at 684.5 nm of a binary alloy can be lower than that of the pure constituent components. For the actual probes it was found that the observed values of normal spectral emissivity of the alloys are in between or higher than those of the pure constituent components. Experiments were conducted on the alloy systems Ni-Ti and Au-Ni. Their emissivity as well as electrical resistivity and enthalpy as a function of temperature is presented.展开更多
Intermetallic compounds(IMC) formed at Sn-Ag-Cu solder droplet/pad interface during wetting reaction were investigated. Comparative studies of the IMC evolution during reflow and aging were also conducted. The results...Intermetallic compounds(IMC) formed at Sn-Ag-Cu solder droplet/pad interface during wetting reaction were investigated. Comparative studies of the IMC evolution during reflow and aging were also conducted. The results show that the wetting reaction between molten solder droplet and pad leads to the formation of Au-Sn compound at interface, but Au element is not fully consumed during wetting reaction. After reflow, all Au layer disappears from the interface, Au element is dissolved into solder and Au-Sn intermetallic compounds are precipitated in the bulk. Reaction between Ni layer and Sn-Ag-Cu solder leads to the formation of (CuxNi1-x)6Sn5 layer at interface during reflow. According to the thermodynamic-kinetic of interfacial reaction, the wetting reaction at solder droplet/pad interface influences the phase selectivity of IMC evolution during reflow and aging process.展开更多
基金Project (51071181) supported by the National Natural Science Foundation of ChinaProject (2010FJ4034) supported by Natural Science Foundation of Hunan Province,China
文摘In the framework of systematic science of alloys,the average molar property（volume and potential energy） functions of disordered alloys were established.From these functions,the average molar property functions,partial molar property functions,derivative functions with respect to composition,general equation of relationship between partial and average molar properties of components,difference equation and constraining equation of different values between partial and average molar properties,as well as general Gibbs-Duhem formula were derived.It was proved that the partial molar properties calculated from various combinative functions of average molar properties of alloys are equal,but in general,the partial molar properties are not equal to the average molar properties of a given component.This means that the partial molar properties cannot represent the corresponding properties of the component.All the equations and functions established in this work were proved to be correct by calculating the results of partial and average atomic volumes of components as well as average atomic volumes of alloys in the Au-Ni system.
基金supported by the National Natural Science Foundation of China (Nos. 51371015 and 51331002)Beijing Municipal Research Project for Outstanding Doctoral Thesis Supervisors (No. 20121000603)+1 种基金Beijing Natural Science Foundation (No. 2142018)the Fundamental Research Funds for the Central Universities (No. FRF-BR-15-009B)
文摘Bimetallic nanomaterials are of great signifi- cance to both fundamental research and industrial appli- cations. Their physicochemical performances are critically dependent on their architectures and electronic structures. Here, it was reported a controlled synthesis of Au/Ni bimetallic nanocrystals with different nanostructures, i.e., dumbbell, core@shell and alloyed nanostructures in a one- pot synthesis procedure. Detailed structural characteriza- tions were conducted with the combination of transmission electron microscopy （TEM） and X-ray diffraction （XRD）. Even there is a large lattice mismatch between Au and Ni, Au@Ni core@shell nanocrystals are obtained with the seeded growth method. The growth mechanism was deeply investigated. Triphenylphosphine is demonstrated to be an effective capping agent to modify the interfacial energy to form core@shell nanocrystals, and the higher temperature is proved to be a key role in obtaining alloyed nanocrystals.
基金This work is financially supported by the "Austrian Science Fund - FWF", Sensengasse 1, 1090 Vienna, under contract No. P15055
文摘In a previous paper it was shown that the normal spectral emissivity at 684.5 nm of a binary alloy can be lower than that of the pure constituent components. For the actual probes it was found that the observed values of normal spectral emissivity of the alloys are in between or higher than those of the pure constituent components. Experiments were conducted on the alloy systems Ni-Ti and Au-Ni. Their emissivity as well as electrical resistivity and enthalpy as a function of temperature is presented.
文摘Intermetallic compounds(IMC) formed at Sn-Ag-Cu solder droplet/pad interface during wetting reaction were investigated. Comparative studies of the IMC evolution during reflow and aging were also conducted. The results show that the wetting reaction between molten solder droplet and pad leads to the formation of Au-Sn compound at interface, but Au element is not fully consumed during wetting reaction. After reflow, all Au layer disappears from the interface, Au element is dissolved into solder and Au-Sn intermetallic compounds are precipitated in the bulk. Reaction between Ni layer and Sn-Ag-Cu solder leads to the formation of (CuxNi1-x)6Sn5 layer at interface during reflow. According to the thermodynamic-kinetic of interfacial reaction, the wetting reaction at solder droplet/pad interface influences the phase selectivity of IMC evolution during reflow and aging process.
