The effect of precipitate free zones along grain boundaries on the yield strength of the nickel-base superalloy NIMONIC PE16

Ti-carbides forming in grain boundries lead to Ti-depleted zones along them. This in turn gives rise to g'-free zones along grain boundaries. The resulting effects on the strength of NIMONIC PE16 are investigated for bi-crystals and polycrystals. The bicrystals have been grown by a zone melting technique and the polycrystals have been produced by thermo-mechanical treatments. The grain boundaries in the bicrystals follow the dendrites. The following work is carried out: growth of bicrystals, analysis of dendrite growth, measurements of the yield strength, and of the widths of the g'-free zones, transmission electron microscopy of the dislocation processes at grain boundaries.

Drittmittelgeber:

Deutsche Forschungsgemeinschaft

Beteiligte Wissenschaftler:

Dr. D. Baither, Dipl.-Phys. T. Herding (bis Januar 2000), Dipl.-Phys. T. Krol, Prof. Dr. E. Nembach, Prof. Dr. R. Reichelt (Institut für Medizinische Physik und Biophysik, WWU)

Veröffentlichungen:

Baither, D., T. Herding, T. Krol, R. Reichelt, E. Nembach: The effects of precipitation free zones on order strengthening in NIMONIC PE16 bicrystals, Proc. Int. Conf. Strength of Materials 12, 2000, Mat. Sci. Eng., in press