New approach to quantifying solidification path in modelling of macrosegregation in multicomponent Al alloys

AbstractThe continuum model Alsim, which computes the macroscopic transport of mass, enthalpy, momentum, and solute in aluminium castings, is being coupled with a new module based on the microsegregation model Alstruc in order to update the solidification path in macrosegregation computations for industrial multicomponent aluminium alloys. The coupling deals with two main challenges; the first being the need for accessing thermodynamical phase diagram data within reasonable limits of computational time and storage. This is solved in Alstruc by approximating the phase diagram data by simple, analytical expressions. The second challenge is that many advanced microsegregation models are restricted to 'closed' volume elements of constant total alloy composition. This is solved by calling the Alstruc module at each nodal point and time step in Alsim and thereby allowing for an 'open system'. The usefulness of the new module is preliminary assessed.