Dresden 2009 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 25: Topical Session High Temperature Materials I
MM 25.6: Vortrag
Mittwoch, 25. März 2009, 12:00–12:15, IFW A
Microstructure and properties of Co-Re-based experimental alloys for high temperature applications — •Debashis Mukherji1, Joachim Rösler1, Rainer Hüttner2, Uwe Glatzel2, Timo Depka3, Christoph Somsen3, Gunther Eggeler3, Manja Krüger4, and Martin Heilmaier4,5 — 1Technische Universität Braunschweig, Braunschweig, Germany — 2Universität Bayreuth, Bayreuth, Germany — 3Ruhr-Universität Bochum, Bochum, Germany — 4Otto-von-Guericke-Universität Magdeburg, Magdeburg, Germany — 5Technische Universität Darmstadt, Darmstadt, Germany
New high temperature materials are needed to substitute Ni-base superalloys above 1200°C. Co-Re based alloys are being developed at TU Braunschweig, for this purpose. Re (high melting) forms a continuous solid solution with Co and increases melting point of Co-alloys. Various hardening mechanisms is explored in Co-Re-Cr-C system; namely solid solution hardening by Re, precipitation strengthening by carbides and composite strengthening by - hard (Re-rich) and soft (Co-rich) phases. Unlike in the conventional Co-alloys, where the matrix is fcc, in Co-Re alloy the matrix is hcp phase. The morphology and distribution of second phases are important parameters for effective strengthening. For application in gas turbine the long term stability of the microstructure and high temperature mechanical properties are important. Study of microstructure stability and mechanical properties at high temperatures on two experimental alloys Co-17Re-23Cr and Co-17Re-23Cr-2.6C [compositions in at%] will be presented.