Isometric heat capacity cv and isobar heat capacity cp of Ru metal in HCP,FCC,BCC and liquid state were calculated by using pure element systematic theory.The results are in good agreement with joint army-navy-air for...Isometric heat capacity cv and isobar heat capacity cp of Ru metal in HCP,FCC,BCC and liquid state were calculated by using pure element systematic theory.The results are in good agreement with joint army-navy-air force(JANAF) experimental value and the calculation result by first-principle(FP) method.But the results have great differences in contrast to Scientific Group Thermodata Europe(SGTE) database.The cause is found that it cannot neglect the electron devotion to heat capacity to adjust cp in one-atom(OA) method.The disparity between OA method and SGTE database was discussed.The main cause is that OA method adopts the crosspoint with iso-Ec-line and iso-a-line in hybritriangle to determine the properties,but SGTE database is obtained by extrapolation from activity measurements and critical assessment of data from a large number of binary system.Thermodynamic properties of Ru metal in HCP,FCC,BCC and liquid state,such as entropy S,enthalpy H and Gibbs energy G were calculated.Therefore,the full description of thermodynamic properties from 0 K to random temperature is implemented.展开更多
In this paper, taking Nb-Mo alloy system as an example, the equations of concentration of characteristic atoms of alloys in BCC structure were obtained on the basis of the idea of systematic science of alloys and the ...In this paper, taking Nb-Mo alloy system as an example, the equations of concentration of characteristic atoms of alloys in BCC structure were obtained on the basis of the idea of systematic science of alloys and the number of coordination atoms. The concentrations of characteristic atoms in B2-NbMo type ordered alloys were calculated as functions of ordering degree（s） and composition Xuo. When S=Smax, the concentrations of characteristic atoms of stoichiometric B2-NbMo intermetallic compound are equal to that of alloys, that is, X8^Nb = 0.5 at, X0^Mo= 0.5 at. As ordering degree decreases, characteristic atoms A8^Nb and A0^Mo of B2-NbMo type ordered alloy split. And the degree of splitting of characteristic atoms increases with the ordering degree decreasing. Therefore, disordered alloys and various types of ordered alloys can be designed.展开更多
基金Project(50954006) supported by the National Natural Science Foundation of ChinaProject(2009GK3152) supported by Natural Science Foundation of Hunan Province, China+2 种基金Project(21KZ) supported by Scientific Research Fund of Hunan Provincial Education Department, ChinaProject supported by the Opening Measuring Fund of Large Precious Apparatus, ChinaProject supported by the State Key Laboratory of Powder Metallurgy, China
文摘Isometric heat capacity cv and isobar heat capacity cp of Ru metal in HCP,FCC,BCC and liquid state were calculated by using pure element systematic theory.The results are in good agreement with joint army-navy-air force(JANAF) experimental value and the calculation result by first-principle(FP) method.But the results have great differences in contrast to Scientific Group Thermodata Europe(SGTE) database.The cause is found that it cannot neglect the electron devotion to heat capacity to adjust cp in one-atom(OA) method.The disparity between OA method and SGTE database was discussed.The main cause is that OA method adopts the crosspoint with iso-Ec-line and iso-a-line in hybritriangle to determine the properties,but SGTE database is obtained by extrapolation from activity measurements and critical assessment of data from a large number of binary system.Thermodynamic properties of Ru metal in HCP,FCC,BCC and liquid state,such as entropy S,enthalpy H and Gibbs energy G were calculated.Therefore,the full description of thermodynamic properties from 0 K to random temperature is implemented.
基金supported by the National Natural Science Foundation of China(Grant No.50954006)Hunan Science and Technology Department (Grant No.2009GK3152)+1 种基金Hunan Provincial Construction Department (Grant No.201012)Hunan Provincial Education Department(Grant No.21KZ)
文摘In this paper, taking Nb-Mo alloy system as an example, the equations of concentration of characteristic atoms of alloys in BCC structure were obtained on the basis of the idea of systematic science of alloys and the number of coordination atoms. The concentrations of characteristic atoms in B2-NbMo type ordered alloys were calculated as functions of ordering degree（s） and composition Xuo. When S=Smax, the concentrations of characteristic atoms of stoichiometric B2-NbMo intermetallic compound are equal to that of alloys, that is, X8^Nb = 0.5 at, X0^Mo= 0.5 at. As ordering degree decreases, characteristic atoms A8^Nb and A0^Mo of B2-NbMo type ordered alloy split. And the degree of splitting of characteristic atoms increases with the ordering degree decreasing. Therefore, disordered alloys and various types of ordered alloys can be designed.
