Potential energies of characteristic atoms on basis of experimental heats of
formation of AuCu and AuCu3 compounds (Ⅱ)
(1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Powder Metallurgy Research Institute, Central South University, Changsha 410083, China;
3. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
4. College of Mechanical Engineering, Xiangtan University, Xiangtan 411105, China)
2. Powder Metallurgy Research Institute, Central South University, Changsha 410083, China;
3. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
4. College of Mechanical Engineering, Xiangtan University, Xiangtan 411105, China)
Abstract: The potential energy sequences of characteristic atoms were separated out by nine potential energy E-functions on the basis of larger experimental heats of formation of the L10-AuCu and L12-AuCu3 compounds only. According to these potential energy sequences of characteristic atoms, the potential energies and heats of formation of disordered Au1−xCux alloys were calculated by corresponding E-functions at 0 K; and the potential energies, heats of formation and critical Tc-temperatures of the order-disorder transitions of L10-AuCu, L12-Au3Cu and L12-AuCu3 compounds, Au3Cu-, AuCu- and AuCu3-type ordered alloys with maximal ordering degrees were also calculated at 0 K. The results obtained by both the first and present parts of this investigation were compared. Comparing the results obtained by nine E-functions, the 5th E(x, 0, σ) function may be chosen for describing thermodynamic properties of the compounds, ordered and disordered phases and for establishing the phase diagram of the Au-Cu system in the future.
Key words: systematic science of alloys; Au-Cu system; potential energy; heat of formation; phase transition temperature