An FP-CVM calculation of pre-precipitation clustering in Al-Cu-Mg-Ag alloys

Trace element additions can efficiently control nucleation and, hence, affect final precipitate structures of metastable coherent second phases. As an improved and self-consistent treatment with respect to the quasi-chemical model [Aiwu Zhu et al. Acta Mater 2004;52:3671], a tetrahedron cluster-variation-method (CVM) based on first principles total energy calculation (FP-CVM) is employed to assess cluster formation prior to the second phase precipitation in Al-Cu-Mg-Ag alloys. The overall lattice elastic relaxation (accommodation of atomic unit cells of different volumes) is taken into account