The Thermodynamic Properties And Point Defects Of Aluminum Intermetallics With EAM

Intermetallics compounds are the ideal structure material for aviation and spaceflight due to its good characteristics, such as outstanding intension, high temperature intension and high elastic model and so on. The investigations of intermetallic compound materials bring new field of fundamental materials science. They not only extend the area for material science, but also provide the stable material basis for modern technology development. So it is very important to predict the thermodynamic properties of the alloys employing theoretical models.Daw and Baskes proposed a so-called embedded atom method based on density functional theory last century. The theory was improved by many scientists. Embedded atom method has been applied to study the thermodynamic properties of alloys successfully. In this work, the parameters of embedded atom method for elements Al, Li, Mg, Ti, Fe, Zr and Ce have been determined by fitting the lattice constants, the cohesive energy, the mono-vacancy formation energy and the bulk modulus of pure elements. The parameters of the pair-potential between two different elements have been determined by fitting to experimental data or results calculated with first principles. The formation enthalpies, the elastic constants and point defects of binary alloys systems and the lattice constants, the cohesive energy and the formation enthalpies for ternary intermetallic compounds have been calculated.1. The model parameters of the general analytic embedded-atom method for Al, Li, Mg, Ti, Fe, Zr and Ce have been determined.2. The parameters of the pair-potential between two different elements have been determined by fitting to experimental data or ab initio results.3. The formation enthalpy for the binary disordered alloys and the formation enthalpy of binary intermetallic compounds are calculated. The calculated results are in agreement with the experiments available and the ab initio results or other theoretical results.4. The elastic constants, vacancy defects and antisite defects of binary intermetallic compounds are calculated. The results show that the defect types are the antisite atoms on either sublattice for nonstoichiometry in intermetallic compounds. The calculated results agree well with the experimental data and other theoretic results available. Some of the calculated results need further verification because there is not data of experiments or theories existed in literatures. 5. The lattice constants, cohesive energy and formation enthalpies for the ternary intermetallic compounds are also calculated. The calculated results are in agreement with the results of phase diagram.