Free Energy Calculation of Al-Li-Mg Alloy from Electron Level

摘要

Based on Thomas-Fermi model£¬the calculation method of free energy for atom cluster with electric field had been found. The change trend of free energy of Al-Li-Mg alloy under the effect of electric field had been calculated systemically and quantitatively. And following results had been given: mostly the free energy of Al3Li andMg5Al8 at aging temperature is lower than that of free energy at solid solution temperature, but once the negative electric field increased to certain degree there will be opposite result. At aging temperature, the free energy ofAl3Li and Mg5Al8 are lower than that of Al-2.14wt.%Li andAl-2.6wt.%Mg. And comparing with 1420 alloy, the electric field promotes the precipitation of Al3Li and restrains the precipitation of Mg5Al8.