Prof. Thomas Böhlke
Johannes Gisy (M.Sc)

Methodological focus: theory and numerics
Specialisation in mechanics desired
FEM knowledge necessary

M.Sc. Johannes Gisy

Topic Description:

When exposed to hydrogen, some metallic materials (e.g. palladium and niobium) form hydrides above a certain concentration. This means that the previously single-phase metal decomposes into two phases, an alpha phase with a low hydrogen concentration and a hydride phase with a very high hydrogen concentration.

Mapping this phenomenon, taking into account the elasto-plastic deformation of the metal, requires the introduction of a non-convex free energy density. In a certain concentration range, the coexistence of two phases corresponds to a minimum free energy. The equilibrium concentrations are shifted by elasto-plastic deformations.