Straining experiments were carried out in situ on single crystals, along soft orientations, at 143 and 300K in order to analyze the glide properties of <001> dislocations. The results showed that dislocations slipped in {110} planes, or in wavy slip surfaces, as a result of intensive cross-slip. This was in agreement with atomistic calculations of the dislocation core structure along the screw orientation. Cross-slip also led to the nucleation of high densities of prismatic loops. Dislocations exhibited kinked shapes with almost no screw portion, in agreement with the results of atomistic and anisotropic elastic calculations. The local stress which was deduced from dislocation curvature was close to that measured in macroscopic experiments. The Peierls frictional forces were low at 300K, but were higher at 144K on edge segments in planes close to {100}. The dislocations emitted at a crack tip were analysed and were compared with those formed in atomistic simulations under similar conditions.

In situ Straining Experiments in NiAl along Soft Orientations, and Comparison with Atomistic Simulations. D.Caillard, C.Vailhé, D.Farkas: Philosophical Magazine A, 1999, 79[3], 723-39