The influence of crystal orientation on the high temperature creep behavior of Ni3(Al,Ti,Ta) was investigated by tensile creep testing under a constant load at a temperature of 1123K. The single crystals were oriented close to [001], [011], [111], [557] and [012]. The results revealed an increasing stationary creep rate from [111] over [011] to [001]. The evolution of the microstructure during creep deformation was studied, using transmission electron microscopy. Only a few systems were active in the primary regime, whereas several slip systems operated in the secondary stage. The habit planes of dislocation pairs separated by antiphase boundary were examined and compared with anisotropic elastic calculations, leading to an explanation for the good creep response of [111]-oriented single crystals.

Observations of Orientation Dependent Creep of Ni3Al. Knobloch, C., Glock, K., Glatzel, U.: Materials Research Society Symposium – Proceedings, 1999, 552, KK9.11.1