Interfaces in metallic systems are complex, planar, defective sites. They control segregation behaviour, heterogeneous nucleation and mechanical materials properties. They must be involved in predictions of the thermo-mechanical microstructure evolution of alloys. Tracing back from interface-related microstructural observation, we interprete various aspects of the underlying interface control, including interface thermodynamics, interface diffusion, interface mobilities, and interface structure. By understanding and evaluating the entity of the interface we use this knowledge for engineering purposes of advanced materials and process optimisation., opens an external URL in a new window