Application of cluster dynamics modeling to the precipitation in aluminum alloys

摘要: Abstract The cluster dynamics method is used to model at the atomic scale kinetics of first order phase transformations. Clusters are embryos growing phase. Their formation from solid solution obtained by solving a set master differential equations. This continuity equation size distribution function and based on inter-cluster solute exchanges. These exchanges, absorption emission atoms, controlled diffusivities free energies. applied here precipitation Al3(Zr, Sc) dispersoids with L12 structure in Al–rich Zr–Sc solutions. Several characteristic features discussed: 1) In ternary alloy, fast (Sc) diffusing species always controls nucleation, contrast classical thermodynamical descriptions. 2) A thermodynamic coupling induces heterogeneous nucleation Zr atoms. 3) segregation outer shell slow diffus...