Fachbereich 11 - Physik
Institut für Materialphysik
Strengthening and Nanostructure of Metals and Alloys

Softening of the commercial g'-strengthened nickel-base superalloys
NIMONIC PE16 and NIMONIC 105 at elevated temperatures

Above about 1050K the yield strength s_y of these superalloys decreases sharply. This limits their technical applicability. The reasons for these softening effects have been investigated experimentally and theoretically. There are two relevant mechanisms: i) dissolution of g'-precipitates, and ii) thermal activation helps dislocations to overcome the g'-precipitates. This has been experimentally investigated by measuring s_y as a function of temperature and strain rate and observing the configurations of dislocations by transmission electron microscopy.

Drittmittelgeber:

Deutsche Forschungsgemeinschaft

Beteiligte Wissenschaftler:

Dipl.-Phys. E. Langmaack, Prof. a. D. Dr. E. Nembach, Dr. J. Pesicka, Dipl.-Phys. A. Vennemann

Veröffentlichungen:

Vennemann, A., E. Langmaack, E. Nembach: On the temperature dependence of the critical resolved shear stress of the g'-strengthened superalloy NIMONIC PE16, Scripta Mater., 46, 723, 2002

Nembach, E., J. Pesicka, E. Langmaack: The high temperature decrease of the yield strength of the g'-strengthened superalloys NIMONIC PE16 and NIMONIC 105, Mat. Sci. Engng. (2003), in press.