Anisotropic creep of Ni 3(AlTiTa)

Abstract

Creep tests with Ni{sub 3}Al single crystals with different orientations close to the edges of the standard orientation triangle were performed. A number of active slip systems was found to contribute to the deformation. Activation of cube slip could be verified. With growing dislocation density more and more active slip systems are activated, interactions occur which lead to a change in the character of the dislocations and an increasing amount of passive glide systems. All slip systems with high Schmid factors (m{sub s} > 0.3) have been activated. These observations give insight in the important role of dislocation interactions in-between different slip systems. The components of an interaction matrix between different slip systems can be extracted by comparing absolute dislocation densities of slip systems as function of plastic strain. These interaction matrix will be needed for a model based on evolution equations for dislocation densities of different slip systems.