Gibbs free energy calculation of Al-Cu-Li alloy with the effect of electric field from electron level

Based on Thomas-Fermi model, the calculation method of Gibbs free energy for atom cluster with electric field had been found. The change trend of Gibbs free energy of Al-Cu-Li alloy under the effect of electric field had been calculated systemically and quantitatively. And following results had been given: near the zero electric field and the side of positive electric field, the Gibbs free energy of Cu₄LiAl₇ compound at aging temperature 460 K was higher than that of Gibbs free energy at solid solution temperature 725 K, but once the negative electric field increased to a certain degree there would be an opposite result. The Gibbs free energy of binary solid solution was increased with the addition of third element lithium or copper, and with the increase of electric field intensity the Gibbs free energy margin of two kinds of solid solution became bigger.