Micromechanical multi-scale approaches are frequently employed to monitor local and global field quantities and their evolution under varying mechanical and/or thermal loading szenarios. In this contribution the importance of an appropriate representation of microstructural features such as grain size, phase fractions and phase arrangement and crystallographic orientation of individual grains is highlighted.

The structure considered is a labyrinth seal system as used in gas turbines responsible to maintain a gas pressure difference between individual turbine stages. Common materials for such applications are nickel-base superalloys (Hastelloy X and Haynes 214). The seal is formed from corrugated sheets soldered to a base plate resulting in honeycombs. During operation of the gas turbine rubbing between the seal and the tip of the turbine blade leads to extreme mechanical and thermal loads that can cause wear and failure of the honeycombs.

An overview of experiments performed on a test rig and extensive numerical simulations on the micro- and macro-structure are presented and discussed. The numerical simulation strategy employed allows to identify optimum microstructures w.r.t. alloy type, grain size and grain orientation and optimum macro-structures w.r.t. wall thickness, shape of the honeycomb and thickness of the soldering layer between adjacent honeycomb walls.