Mukherji, D.; Rösler, J.; Strunz, P.; Gilles, R.; Schumacher, G.; Piegert, S.: Beyond Ni-based superalloys: Development of CoRe-based alloys for gas turbine applications at very high temperatures. International Journal of Materials Research 102 (2011), p. 1125-1132
High temperature material development is mainly driven by gas turbine needs. Today, Ni-based superalloys are the dominant materials class in the hot section of turbines. Material development will continue to push the maximum service temperature of Ni-superalloys upwards. However, this approach has a fundamental limit and cannot be sustained indefinitely, as the Ni-superalloys are already used very close to their melting point. Within the framework of the DFG Forschergruppe program (FOR 727) - "Beyond Ni-base superalloys" - CoRe based alloys are being developed at the Technische Universität Braunschweig as a new generation of high temperature materials that can be used at +100°C above single crystal Ni-suberalloys. Two main strengthening concepts, namely precipitation hardening by MC carbides and composite hardening by Co2Re3-type sigma phase are being explored in Core alloy development. Selected results of microstructural characterizations, including in-situ measurements by synchrotron and neutron scattering are presented.