An FP-CVM calculation of pre-precipitation clustering in AlCuMgAg 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 AlCuMgAg alloys. The overall lattice elastic relaxation (accommodation of atomic unit cells of different volumes) is taken into account.