The improved form of calculation formula for the activities of the components in binary liquids and solid alloys has been derived based on the free volume theory considering excess entropy and Miedema's model for ...The improved form of calculation formula for the activities of the components in binary liquids and solid alloys has been derived based on the free volume theory considering excess entropy and Miedema's model for calculating the formation heat of binary alloys. A calculation method of excess thermodynamic functions for binary alloys, the formulas of integral molar excess properties and partial molar excess properties for solid ordered or disordered binary alloys have been developed. The calculated results are in good agreement with the experimental values.展开更多
A new method of revising activity values has been derived based on the so called correction factor function for binary alloys with a large difference between two components. The correction factor is a function of phys...A new method of revising activity values has been derived based on the so called correction factor function for binary alloys with a large difference between two components. The correction factor is a function of physical properties formed by the difference of two components. Its absolute value increases with the enhancement of the difference in the character of components. It can be either positive or negative and the rules for selecting the sign of correction factor have been analyzed. Results are in good agreement with the experimental values.展开更多
The Gibbs-Bogoliubov （GB） inequality is applied to investigate the thermodynamic properties of some equiatomic noble metal alloys in liquid phase such as Au-Cu, Ag-Cu, and Ag-Au using well recognized pseudopotential...The Gibbs-Bogoliubov （GB） inequality is applied to investigate the thermodynamic properties of some equiatomic noble metal alloys in liquid phase such as Au-Cu, Ag-Cu, and Ag-Au using well recognized pseudopotential formalism. For description of the structure, well known Percus-Yevick （PY） hard sphere model is used as a reference system. By applying a variation method the best hard core diameters have been found which correspond to minimum free energy. With this procedure the thermodynamic properties such as entropy and heat of mixing have been computed. The influence of local field correction function viz; Hartree （H）, Taylor （T）, lehimaru-Utsumi （IU）, Farid et al. （F）, and Sarkar et al. （S） is also investigated. The computed results of the excess entropy compares favourably in the case of liquid alloys while the agreement with experiment is poor in the case of heats of mixing. This may be due to the sensitivity of the heats of mixing with the potential parameters and the dielectric function.展开更多
In order to further verify the accuracy and feasibility of the calculated mass action concentrations Ni of Al and Fe by the developed atom and molecule coexistence theory(AMCT)model,i.e.,AMCT-N,model,for representing ...In order to further verify the accuracy and feasibility of the calculated mass action concentrations Ni of Al and Fe by the developed atom and molecule coexistence theory(AMCT)model,i.e.,AMCT-N,model,for representing activities aR,i of Al and Fe in Fe-Al binary melts reported in the first part of the serial studies,the molar mixing thermodynamic functions of Fe-Al binary melts over a temperature range from 1823 to 1973 K have been calculated based on Ni of Al and Fe as well as the effect of temperature on activity coefficients 7,of Al and Fe as■lnγj/■T=■ln(Ni/xi)/dT by the developed AMCTN-Ni model,where T is absolute temperature and.v,is the mole fraction of element i or compound i in metallic melts.The reported molar mixing thermodynamic functions of Fe-Al binary melts as well as the reported excess molar mixing thermodynamic functions of Fe-Al binary melts relative to ideal solution as a basis from the available literatures have been critically assessed and applied as criteria to verify the developed AMCT-Al,model.The effect of changing temperature onγi of Al and Fe,i.e.,activity coefficient gradients■lnγAl/■T and■lnγFe/■T,which are two indispensable parameters to calculate the molar mixing thermodynamic functions of Fe-Al binary melts,can be accurately obtained by the developed AMCT-Ni,model and expressed by the cubic polynomial functions.Not only the partial molar mixing thermodynamic functions of Al and Fe in Fe-Al binary melts but also the integral molar mixing thermodynamic functions of Fe-Al binary melts can be accurately calculated by the developed AMCT-Al,model.Furthermore,the excess partial and integral molar mixing thermodynamic functions of Fe-Al binary melts relative to ideal solution as a basis can also be precisely calculated by the developed AMCT-Ni,model.展开更多
The approach recently proposed by Liu and Qu was extended to correlate excess enthalpies of highly asymmetric binary systems.In this approach,FRKS equation of state was used, and Lij（T,x）function was applied in plac...The approach recently proposed by Liu and Qu was extended to correlate excess enthalpies of highly asymmetric binary systems.In this approach,FRKS equation of state was used, and Lij（T,x）function was applied in place of single value of the binary interaction parameter Lij.Twenty four binary systems,including benzene -(C11～C17)lakane,benzene -methyl naphthalene,xylene-（C3～C8）al-cohol,l-Hepetanol-（C6～C9）alkane,methanol,ethanol-chlorobenzene,were selected to do the test.For most of these binary systems, no equation of state method has been found accurate.The results obtained show that this method can improve significantly the correlation of excess enthalpies for highly asymmetric binary systems.The calculated excess enthalpies for most of the selected systems are in good agreement with experimental data.展开更多
基金Financial support of this research by the National Natural Sci-ence Foundation of China under Grants 50074013 and 59774027Huo Ying-Dong Education Foundation is gratfully scknowl-edged.Thanks are furthermore due to Chinese-Austrian Scientific Technicai Exchange Prograrn(Project V.A.15) as well as to Prof.T.Tanaka in Osaka University in Japan and Dr.S.J.Zhong foroffering help and discuasions.
文摘The improved form of calculation formula for the activities of the components in binary liquids and solid alloys has been derived based on the free volume theory considering excess entropy and Miedema's model for calculating the formation heat of binary alloys. A calculation method of excess thermodynamic functions for binary alloys, the formulas of integral molar excess properties and partial molar excess properties for solid ordered or disordered binary alloys have been developed. The calculated results are in good agreement with the experimental values.
基金Financial support of this research by the National Natural Sci-ence Foundation of China under Grants 50074013 and 59774027and Huo Ying-Dong Education Foundation is gratefully acknowl-edged. Thanks are furthermore due to Chinese-Austrian Scientific Techni
文摘A new method of revising activity values has been derived based on the so called correction factor function for binary alloys with a large difference between two components. The correction factor is a function of physical properties formed by the difference of two components. Its absolute value increases with the enhancement of the difference in the character of components. It can be either positive or negative and the rules for selecting the sign of correction factor have been analyzed. Results are in good agreement with the experimental values.
文摘The Gibbs-Bogoliubov （GB） inequality is applied to investigate the thermodynamic properties of some equiatomic noble metal alloys in liquid phase such as Au-Cu, Ag-Cu, and Ag-Au using well recognized pseudopotential formalism. For description of the structure, well known Percus-Yevick （PY） hard sphere model is used as a reference system. By applying a variation method the best hard core diameters have been found which correspond to minimum free energy. With this procedure the thermodynamic properties such as entropy and heat of mixing have been computed. The influence of local field correction function viz; Hartree （H）, Taylor （T）, lehimaru-Utsumi （IU）, Farid et al. （F）, and Sarkar et al. （S） is also investigated. The computed results of the excess entropy compares favourably in the case of liquid alloys while the agreement with experiment is poor in the case of heats of mixing. This may be due to the sensitivity of the heats of mixing with the potential parameters and the dielectric function.
基金This work is supported by the Beijing Natural Science Foundation(Grant No.2182069)the National Natural Science Foundation of China(Grant No.51174186).
文摘In order to further verify the accuracy and feasibility of the calculated mass action concentrations Ni of Al and Fe by the developed atom and molecule coexistence theory(AMCT)model,i.e.,AMCT-N,model,for representing activities aR,i of Al and Fe in Fe-Al binary melts reported in the first part of the serial studies,the molar mixing thermodynamic functions of Fe-Al binary melts over a temperature range from 1823 to 1973 K have been calculated based on Ni of Al and Fe as well as the effect of temperature on activity coefficients 7,of Al and Fe as■lnγj/■T=■ln(Ni/xi)/dT by the developed AMCTN-Ni model,where T is absolute temperature and.v,is the mole fraction of element i or compound i in metallic melts.The reported molar mixing thermodynamic functions of Fe-Al binary melts as well as the reported excess molar mixing thermodynamic functions of Fe-Al binary melts relative to ideal solution as a basis from the available literatures have been critically assessed and applied as criteria to verify the developed AMCT-Al,model.The effect of changing temperature onγi of Al and Fe,i.e.,activity coefficient gradients■lnγAl/■T and■lnγFe/■T,which are two indispensable parameters to calculate the molar mixing thermodynamic functions of Fe-Al binary melts,can be accurately obtained by the developed AMCT-Ni,model and expressed by the cubic polynomial functions.Not only the partial molar mixing thermodynamic functions of Al and Fe in Fe-Al binary melts but also the integral molar mixing thermodynamic functions of Fe-Al binary melts can be accurately calculated by the developed AMCT-Al,model.Furthermore,the excess partial and integral molar mixing thermodynamic functions of Fe-Al binary melts relative to ideal solution as a basis can also be precisely calculated by the developed AMCT-Ni,model.
文摘The approach recently proposed by Liu and Qu was extended to correlate excess enthalpies of highly asymmetric binary systems.In this approach,FRKS equation of state was used, and Lij（T,x）function was applied in place of single value of the binary interaction parameter Lij.Twenty four binary systems,including benzene -(C11～C17)lakane,benzene -methyl naphthalene,xylene-（C3～C8）al-cohol,l-Hepetanol-（C6～C9）alkane,methanol,ethanol-chlorobenzene,were selected to do the test.For most of these binary systems, no equation of state method has been found accurate.The results obtained show that this method can improve significantly the correlation of excess enthalpies for highly asymmetric binary systems.The calculated excess enthalpies for most of the selected systems are in good agreement with experimental data.
