Bernard Fedelich, Abteilung V, Werkstofftechnik, Bundesanstalt für Materialforschung und -prüfung, Berlin, Germany
Ni-base single crystal superalloys are widely used as blade materials in the hottest section of gas turbines or aero-engines. For structural analysis and life prediction of the components, a description of the inelastic behaviour of the alloy in a wide temperature range is required. However, despite the number of papers published in this area, the modelling of these alloys still constitutes a challenge for material modellers for several reasons:
- Multiple deformation mechanisms can operate simultaneously and their activation can depend on temperature or stress level.
- The deformation behaviour strongly depends on the crystal orientation.
- Finally the morphology becomes unstable at high temperature and the degraded microstructure behaves differently than the initial one.