Thermodynamic calculation of Er-X and Al-Er-X compounds existing in Al-Mg-Mn-Zr-Er alloy

Based on the Miedema model and Extended Miedema theory,the formation energies of different solute components in Er-X binary system and Al-Er-X ternary systems were calculated.The results show that the variation of erbium content has little influence on the chance rate of the formation Al-Er compound in the Al-Mg-Mn-Zr-Er system.The calculated formation energies in the Er-X binary system and Al-Er-X ternary systems indicate that Al3Er phase can take priority of depositing,Al-Er-Zr ternary compounds may also found which agrees with the experimental results in references.The consistency of calculation and experiment proves that the intermetallic compounds in the Al-Mg-Mn-Zr-Er system can be predicted directly by calculating the formation energies of the reactions in Er-X binary system and Al-Er-X ternary systems with the Miedema model and Extended Miedema theory.

Composition Range of Amorphous Mg-Ni-Y Alloys

Based on the thermodynamic point of view, a method for predication of the composition range of amorphous ternary alloys was proposed. The composition range of amorphous ternary alloys is determined by the comparison of the excess free energy of the amorphous alloy and the free energy of competing crystalline states. The free energy is extrapolated from the data of three binary alloys by using Toop′s model. The method was applied to predict the composition range of amorphous Mg Ni Y alloys. The theoretical results are in good agreement with the available experimental results. It indicates that the present method can be used to predict the composition range for amorphous ternary alloys.

Formation Enthalpies of Ce-Th-Yb Calculated with EAM

The parameters of embedded atom method for elements Ce, Th and Yb were determined by fitting the lattice constants, the cohesive energy, the monovacancy formation energy and the bulk modulus of elements. The alloy potential was taken as the form of Johnson′s. The formation enthalpies of Th-Ce, Th-Yb and Ce-Yb binary alloys systems and Ce-Th-Yb ternary alloy were calculated with the present embedded atom potentials. The calculations for binary alloys are in good agreement with the results calculated with Miedema′s theory. As for the ternary alloy, the calculated formation enthalpies are in good agreement with those extrapolated from the formation enthalpies of constitutive binary alloys by Toop′s model.

Phase evolution of binary immiscible Al-Sn film

Binary immiscible Al-Sn alloy is a very important potential anode material for lithium ion batteries.The phase stability and separation process of Al-Sn film,fabricated by magnetron co-sputtering method,was investigated by X-ray diffractometer(XRD),differential scanning calorimetry(DSC) and in situ transmission electron microscopy(TEM) and explained by Miedema theoretical model.Thermodynamic analysis reveals that the asdeposited Al-Sn film will decompose spontaneously into Al-riched areas and Sn-riched areas because of the positive mixing enthalpy.The crystallization process takes place when the Al content in the Al-riched area or Sn content in the Sn-riched area increases.Experimental results show that Al-Sn thin film is composed of an amorphous matrix and well-dispersed composite nanoparticles.Every particle contains an Al-riched area and a Sn-riched area.The Snriched area crystallizes and swallows up the Al-riched area gradually during heating through uphill diffusion of the Sn atoms.Based on the theoretical analysis and experimental results,an empirical model to explain the phase evolution process in the Al-Sn film was proposed.