Plastic flow resistance of NiTiCu shape memory alloy-theory and experiments

Abstract The NiTiCu alloys belong to a class of materials with excellent shape memory properties. The limitations in shape memory properties arise due to onset of slip at interfaces and also in austenite domains. As slip mediated plasticity is a source of irreversibility, it is imperative to understand the glide resistance of austenite which can be rather complex. In this paper, we develop a model to precisely derive the CRSS for slip substantiated with the uniaxial loading experiments on single crystals in a wide range of orientations employing Digital Image Correlation. We illustrate the core spreading of {011} dislocations and evaluate the role of non-Schmid stress components which introduces profound anisotropy in CRSS levels. The model matches the experimental findings in single crystals with excellent agreement. The theory and experiments show significant crystal orientation dependence of plasticity which must be taken into account when designing with these alloys.